Construction of an electrochemical pH sensor using one-pot synthesis of a molybdenum diselenide/nitrogen doped graphene oxide screen-printed electrode

In this study, a one-pot synthesis of a molybdenum diselenide/nitrogen-doped graphene oxide (MoSe2/NGO) composite was demonstrated and used for the fabrication of an electrochemical pH sensor. The MoSe2/NGO composite was characterized using powder X-ray diffraction, infrared spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and Brunauer-Emmett-Teller analysis. The electrochemical behavior at different pH values was determined by recording the open-circuit potential. When applied for pH detection, the MoSe2/NGO modified screen-printed electrode (SPE) showed good linearity with a sensitivity of 61.3 mV pH-1 over a wide pH range of 2-14. In addition, the pH sensor exhibited a remarkably stable response, high reproducibility, and selectivity. The sensor was used to measure the acidity or alkalinity of real food and beverage samples. The results for these samples showed a relative error of less than 10% compared with the results obtained with the commercial pH meter. The portable sensor produced by screen printing electrodes paves the way for the development of simple, cost-effective, real-time, and robust pH sensors for the pH analysis of various sample matrices for clinical diagnostics, biosensing, and cost-effective applications.

Switchable Metal-Ion Selectivity in Sulfur-Functionalised Pillar[5]arenes and Their Host-Guest Complexes

Nucleophilic substitution of pertosylated pillar[5]arene (P-OTs) with commercially available sulfur containing nucleophiles (KSCN, KSAc, and thiophenol), yields a series of sulfur-functionalised pillar[5]arenes. DLS results and SEM images imply that these pillararene macrocycles self-assemble in acetonitrile solution, while X-ray crystallographic evidence suggests solvent-dependent assembly in the solid state. The nature of the sulfur substituents decorating the rim of the pillararene controls binding affinities towards organic guest encapsulations within the cavity and dictates metal-ion binding properties through the formation of favorable S-M2+ coordination bonds outside the cavity, as determined by 1 H NMR and fluorescence spectroscopic experiments. Addition of a dinitrile guest containing a bis-triazole benzene spacer (btn) induced formation of pseudorotaxane host-guest complexes. Fluorescence emission signals from these discrete macrocycles were significantly attenuated in the presence of either Hg2+ or Cu2+ in solution. Analogous titrations utilizing the corresponding pseudorotaxanes alter the binding selectivity and improve fluorescence sensing sensitivity. In addition, preliminary liquid-liquid extraction studies indicate that the macrocycles facilitate the transfer of Cu2+ from the aqueous to the organic phase in comparison to extraction without pillar[5]arene ligands.

Improving spin crossover characteristics in heteroleptic [FeIII(qsal-5-I)(qsal-5-OMe)]A complexes

A family of heteroleptic spin crossover (SCO) [FeIII(qsal-5-I)(qsal-5-OMe)]A·sol (qsal-5-X = 5-X-2-[(8-quinolylimino)methyl]phenolate; A = NO3-1 sol = 2MeOH, NCS-2 sol = 0.75MeOH·1.3H2O, BF4-3 sol = MeOH, OTf-4, sol = MeOH) complexes have been synthesized. Most of the complexes exhibit gradual SCO, with the exception of NCS, which is principally high spin. In contrast, the OTf complex shows an abrupt hysteretic SCO (35 K) after solvent loss. The magnetic properties of this complex are significantly improved in comparison to the related homoleptics, [Fe(qsal-I)2]OTf 5 (hysteresis, 8 K) and [Fe(qsal-5-OMe)2]OTf·CH2Cl26 (gradual SCO). Structural studies reveal that slight changes in the crystal packing cause stronger interactions improving the cooperativity. These findings are supported by DFT calculations using the r2SCAN functional in which the calculated structures show that SCO from the LS to the HS state causes pronounced scissoring of the 1D π-π chains and substantial changes in their relative orientation following loss of MeOH.

Spatial Disadvantage and Racial Disparities in Gun Homicides

A spatially disadvantaged census tract is one that is surrounded by disadvantaged tracts. More spatially disadvantaged neighborhoods may experience more violence, independent of their own level of disadvantage, and majority Black middle-class neighborhoods are more likely to be spatially disadvantaged than majority white neighborhoods. The purpose of this paper is to study how much of the racial difference in gun homicide rates between majority Black and majority white middle-class neighborhoods can be explained by differences in spatial disadvantage. To study this, comparable majority Black and majority white tracts were matched to understand how gun homicide rates differ in neighborhoods with similar levels of disadvantage. Further matching on spatial disadvantage reduced the disparity in gun homicides between majority Black and majority white middle-class neighborhoods, suggesting that spatial disadvantage accounts for some but not all of the disparity.

Bidirectional photoswitchability in an iron(iii) spin crossover complex: symmetry-breaking and solvent effects

The impact of solvent on spin crossover (SCO) behaviour is reported in two solvates [Fe(qsal-I)₂]NO₃·2ROH (qsal-I = 4-iodo-2-[(8-quinolylimino)methyl]phenolate; R = Me 1 or Et 2) which undergo abrupt and gradual SCO, respectively. A symmetry-breaking phase transition due to spin-state ordering from a [HS] to [HS-LS] state occurs at 210 K in 1, while T_1/2 = 250 K for the EtOH solvate, where complete SCO occurs. The MeOH solvate exhibits LIESST and reverse-LIESST from the [HS-LS] state, revealing a hidden [LS] state. Moreover, photocrystallographic studies on 1 at 10 K reveal re-entrant photoinduced phase transitions to a high symmetry [HS] phase when irradiated at 980 nm or a high symmetry [LS] phase after irradiation at 660 nm. This study represents the first example of bidirectional photoswitchability and subsequent symmetry-breaking from a [HS-LS] state in an iron(iii) SCO material.

Schomburginones A‒J, geranylated benzophenones from the leaves of Garcinia schomburgkiana and their cytotoxic and anti-inflammatory activities

Ten undescribed benzophenones, schomburginones A-J, together with 14 known analogs were isolated from the leaves of Garcinia schomburgkiana, an edible plant native to the Indochina region. The structures of the undescribed compounds were elucidated by NMR combined with HRMS spectroscopy, while their absolute configurations were determined using ECD and single-crystal X-ray diffraction analysis. The isolated metabolites represent benzophenone derivatives containing a modified monoterpene unit, including tri- and tetracyclic skeletons, which are rarely found in genus Garcinia. The cytotoxic evaluation on three cancerous cell lines demonstrated that schomburginone G, schomburginone H, and 3-geranyl-2,4,6-trihydroxybenzophenone were active against HeLa cells with IC₅₀ values in the range of 12.2-15.7 μM, respectively, and selective compared to the non-cancerous L929 cells (SI > 3.5). In addition, the three cytotoxic compounds together with clusiacyclol A showed significant NO inhibitory activity in RAW 264.7 macrophage cells over 85% inhibition without obvious cytotoxicity at a final concentration of 100 μM. The promising activities of these compounds in cytotoxic and anti-inflammatory assays make them attractive for further study in the development of anticancer drugs.

Critical Faculty and Peer Instructor Development: Core Components for Building Inclusive STEM Programs in Higher Education

First-generation college students and those from ethnic groups such as African Americans, Latinx, Native Americans, or Indigenous Peoples in the United States are less likely to pursue STEM-related professions. How might we develop conceptual and methodological approaches to understand instructional differences between various undergraduate STEM programs that contribute to racial and social class disparities in psychological indicators of academic success such as learning orientations and engagement? Within social psychology, research has focused mainly on student-level mechanisms surrounding threat, motivation, and identity. A largely parallel literature in sociology, meanwhile, has taken a more institutional and critical approach to inequalities in STEM education, pointing to the macro level historical, cultural, and structural roots of those inequalities. In this paper, we bridge these two perspectives by focusing on critical faculty and peer instructor development as targets for inclusive STEM education. These practices, especially when deployed together, have the potential to disrupt the unseen but powerful historical forces that perpetuate STEM inequalities, while also positively affecting student-level proximate factors, especially for historically marginalized students.

Derrisrobustones A-D, isoflavones from the twig extract of Derris robusta (DC.) Benth. and their α-glucosidase inhibitory activity

Three previously undescribed isoflavones, derrisrobustones A-C, and a previously undescribed natural isoflavone, derrisrobustone D, along with eight known isoflavones, were isolated from the twig extract of Derris robusta (DC.) Benth. All structures were identified by extensive spectroscopic analysis. Derrisrobustones A-C were obtained as scalemic mixtures and were resolved by chiral HPLC. The (1″R, 2″R) absolute configuration of (+)-derrisrobustone B was established by single-crystal X-ray crystallography using Cu Kα radiation. The absolute configurations of derrisrobustones A and C were determined by analysis of experimental and calculated ECD data. All compounds were evaluated for their α-glucosidase inhibitory activity. Of these, derrubone displayed the best α-glucosidase inhibitory activity with an IC₅₀ value of 64.2 μM.

Structural and theoretical insights into solvent effects in an iron(III) SCO complex

Alcohol effects in a series of iron(III) spin crossover complexes [Fe(qsal-Cl)2]NO3·ROH (R = Me 1, Et 2, 1-Pr 3) are explored. Despite the solvents differing from each other by only...

Neutral Isocyanide-Templated Assembly of Pillar[5]arene [2] and [3]Pseudorotaxanes

Unprecedented pillar[5]arene–isocyanide pseudorotaxane inclusion complexes are reported. Extensive 1H-NMR experiments reveal remarkably strong binding affinities of alkyl diisocyanide guests (Ka >105 M-1 in CDCl3) by pillar[5]arenes. Characterised by multinuclear 1H...

Preparation and physicochemical characterization of sildenafil cocrystals

Sildenafil is a specific inhibitor of the phosphodiesterase type 5 (PDE-5) enzyme that protects cyclic guanosine monophosphate from breakdown by PDE-5. It is a biopharmaceutical categorization system Class II medication with low bioavailability because it is almost insoluble in water. The objectives of this study were to prepare sildenafil cocrystals with co-former molecules including aspirin (acetylsalicylic acid [ASA]), fumaric acid (FMA), and benzoic acid (BZA) to improve the water solubility of sildenafil. The cocrystals were prepared by antisolvent addition (AA) and slow solvent evaporation (SE) methods. The stoichiometric ratios of sildenafil and co-former molecules were varied. The obtained crystals were characterized by stereomicroscope, Fourier transformed infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), and powder X-ray diffraction (PXRD). The water solubility of sildenafil cocrystals was compared with sildenafil base. In the AA method, the crystals only form in sildenafil-ASA reaction. These crystals were not cocrystals between sildenafil and ASA because they were formed to new substances that were confirmed by single-crystal X-ray diffraction. In the SE method, the cocrystals were successfully prepared in the reaction of sildenafil with ASA, FMA, and BZA which use acetone or ethyl acetate as a solvent. The obtained crystals are irregular shapes and their FT-IR, NMR, and PXRD results exhibited the characteristics of sildenafil and its co-former. The stoichiometric ratios of sildenafil and co-formers after cocrystallization were different from an initial of crystallization. The sildenafil cocrystals with ASA, FMA, and BZA by SE method had higher water solubility than sildenafil base. The sildenafil-FMA cocrystals had the highest water solubility and increased up to five times when compared with sildenafil base.

Abyssomicin derivatives from the rhizosphere soil actinomycete Microbispora rhizosphaerae sp. nov. TBRC6028

Three undescribed abyssomicin derivatives, including microbimisin, abyssomicins Z1, and Z2, were isolated from the soil actinomycete Microbispora rhizosphaerae sp. nov. TBRC6028. Chemical structures were determined by NMR spectroscopic data (¹H, ¹³C, COSY, HSQC, HMBC, and NOESY spectra) and the absolute configurations were verified by single-crystal X-ray diffraction analyses together with the ECD spectral data. Microbimisin and abyssomicin Z1 exhibited weak antibacterial activity against Bacillus cereus with MIC values of 25.0 and 50.0 μg/mL without cytotoxicity against MCF-7 and Vero cells at the concentration of 50 μg/mL.

Race and the Geography of Opportunity in the Post-Prison Labor Market

Research on racial disparities in post-prison employment has primarily focused on the differential effects of stigma on blacks and whites, but we otherwise know little about racial differences. This paper examines racial differences in post-prison employment by industry and geography. We find that the formerly incarcerated are most likely to find work in a small number of "felon-friendly" industries with formerly incarcerated whites having higher employment rates than blacks. Whites are more likely to be employed in felon-friendly industries associated with the primary labor market, particularly construction and manufacturing, which have higher wages and more job stability. To explain these racial differences, we investigate the degree to which employment among the formerly incarcerated is related to where felon-friendly employers are located and where individuals who work in felon-friendly industries live. We find that post-prison employment is associated more with proximity to workers in felon-friendly industries than with proximity to employers. Because formerly incarcerated whites are more likely to live near current workers in felon-friendly industries, the geography of opportunity in the post-prison labor market contributes to the racial disparity in post-prison employment.

EVALUATING CONTRADICTORY EXPERIMENTAL AND NON-EXPERIMENTAL ESTIMATES OF NEIGHBORHOOD EFFECTS ON ECONOMIC OUTCOMES FOR ADULTS

Although non-experimental studies find robust neighborhood effects on adults, such findings have been challenged by results from the Moving to Opportunity (MTO) residential mobility experiment. Using a within-study comparison design, this paper compares experimental and non-experimental estimates from MTO and a parallel analysis of the Panel Study of Income Dynamics (PSID). Striking similarities were found between non-experimental estimates based on MTO and PSID. No clear evidence was found that different estimates are related to duration of adult exposure to disadvantaged neighborhoods, non-linear effects of neighborhood conditions, magnitude of the change in neighborhood context, frequency of moves, treatment effect heterogeneity, or measurement, although uncertainty bands around our estimates were sometimes large. One other possibility is that MTO-induced moves might have been unusually disruptive, but results are inconsistent for that hypothesis. Taken together, the findings suggest that selection bias might account for evidence of neighborhood effects on adult economic outcomes in non-experimental studies.

Interplay of halogen and hydrogen bonding in a series of heteroleptic iron(iii) complexes

The impact of the halogen substituent on supramolecular preferences that influence packing is explored in a series of heteroleptic iron(iii) complexes.

OctaDist: a tool for calculating distortion parameters in spin crossover and coordination complexes

OctaDist is an interactive and visual program for determination of structural distortion in octahedral coordination complexes such as spin crossover complexes, single-ion magnets, perovskites or metal-organic frameworks. OctaDist computes the octahedral distortion parameters initially designed in the context of the spin-crossover phenomenon and denoted ζ, Σ, and Θ from standard structural files. The program also provides additional tools for molecular analyses and visualization. It emphasizes performance, flexibility, ease of use, application programming interface (API) consistency, and clear documentation. The modules and classes in OctaDist can be easily customized to include new algorithms or analytical tools. OctaDist is cross-platform supported for modern operating systems and is available as open-source distributed under the GNU General Public License version 3.

The association of criminal justice supervision setting with overdose mortality: a longitudinal cohort study

BACKGROUND AND AIMS

Despite the high prevalence of substance use among people in the US criminal justice system, little is known about the incidence of overdose mortality by use patterns, drug convictions and supervision setting. We examined the associations between these characteristics and overdose mortality.

DESIGN

Retrospective cohort study.

SETTING AND PARTICIPANTS

Individuals sentenced to prison, jail, probation or jail plus probation for a felony conviction in Michigan, USA from 2003 to 2006.

MEASUREMENTS

Using the National Death Index, we assessed overdose mortality to December 2012. We calculated overdose mortality rates by pre-sentence opioid use, drug convictions and supervision setting. Multivariable analyses were conducted using competing risks regression with time-varying covariates.

FINDINGS

Among 140 266 individuals followed over a mean of 7.84 years [standard deviation (SD) = 1.52], 14.9% of the 1131 deaths were due to overdose (102.8 per 100 000 person-years). Over the follow-up, more than half of overdose deaths occurred in the community (57.7%), nearly a third (28.8%) on probation and 12.8% on parole. The adjusted risk of overdose death was lower on probation [hazard ratio (HR) = 0.71, 95% confidence interval (CI) = 0.60, 0.85] than in the community without probation or parole (HR = 1.00) but not significantly different on parole (HR = 1.13, 95% CI = 0.87, 1.47). Pre-sentence daily opioid use (HR = 3.54, 95% CI = 3.24, 3.87) was associated with an increased risk. Drug possession (HR = 1.11, 95% CI = 0.93, 1.31) and delivery convictions (HR = 0.92, 95% CI = 0.77, 1.09) were not significantly associated with overdose mortality.

CONCLUSIONS

Based on the absolute or relative risk, parole, probation and community settings are appropriate settings for enhanced overdose prevention interventions. Ensuring that individuals with pre-sentence opioid use have access to harm reduction and drug treatment services may help to prevent overdose among people involved with the criminal justice system.

Room temperature conductance switching in a molecular iron(iii) spin crossover junction

Herein, we report the first room temperature switchable Fe(iii) molecular spin crossover (SCO) tunnel junction. The junction is constructed from [Fe^III(qsal-I)₂]NTf₂ (qsal-I = 4-iodo-2-[(8-quinolylimino)methyl]phenolate) molecules self-assembled on graphene surfaces with conductance switching of one order of magnitude associated with the high and low spin states of the SCO complex. Normalized conductance analysis of the current–voltage characteristics as a function of temperature reveals that charge transport across the SCO molecule is dominated by coherent tunnelling. Temperature-dependent X-ray absorption spectroscopy and density functional theory confirm the SCO complex retains its SCO functionality on the surface implying that van der Waals molecule—electrode interfaces provide a good trade-off between junction stability while retaining SCO switching capability. These results provide new insights and may aid in the design of other types of molecular devices based on SCO compounds.

Herein, we report the first room temperature switchable Fe(iii) molecular spin crossover (SCO) tunnel junction.

Neighborhood Racial Composition and Gun Homicides

This cross-sectional study examines disparities in gun homicide rates among neighborhoods of different racial composition for fixed levels of socioeconomic status.

Conformational polymorphism in a cobalt(II) dithiocarbamate complex

Two conformational polymorphs of (N,N-dibutyldithiocarbamato-κ²S,S')[tris(3,5-diphenylpyrazol-1-yl-κN²)hydroborato]cobalt(II), [Co(C₄₅H₃₄BN₆)(C₉H₁₈NS₂)] or [Tp^Ph2Co(S₂CNBu₂)], 1, are accessible by recrystallization from dichloromethane-methanol to give orthorhombic polymorph 1a, while slow evaporation from acetonitrile produces triclinic polymorph 1b. The two polymorphs have been characterized by IR spectroscopy and single-crystal X-ray crystallography at 150 K. Polymorphs 1a and 1b crystallize in the orthorhombic space group Pbca and the triclinic space group P-1, respectively. The polymorphs have a trans (1a) and cis (1b) orientation of the butyl groups with respect to the S₂CN plane of the dithiocarbamate ligand, which results in an intermediate five-coordinate geometry for 1a and a square-pyramidal geometry for 1b. Hirshfeld surface analysis reveals minor differences between the two polymorphs, with 1a exhibiting stronger C-H...S interactions and 1b favouring C-H...π interactions.

Pertosylated pillar[5]arene: self-template assisted synthesis and supramolecular polymer formation

A facile synthesis of decatosylate pillar[5]arene 1 is reported in excellent yield (>70%). The high yield is attributed to a self-template effect of the pendant tosylate arms. The X-ray crystal structure shows the formation of a linear supramolecular polymer, stabilised by intermolecular pillar[5]arene-tosylate inclusion complexes. These polymeric arrays persist in solution and form rod-like microfibril nanostructures evidenced by SEM.

Secondary metabolites from cultures of the ant pathogenic fungus Ophiocordyceps irangiensis BCC 2728

Five new compounds, iranginins A-E (1-5), together with sixteen known compounds were isolated from the insect pathogenic fungus Ophiocordyceps irangiensis BCC 2728. The structures and the absolute configurations of the new compounds were established by spectroscopic analyses, the application of modified Mosher's method (for 2), ECD calculation (for 5), and X-ray crystallographic analysis (for 4). LL-Z1640-5 and mucorisocoumarin C were active against Mycobacterium tuberculosis (MIC 41.7 and 85.0 µM, respectively), while peyroisocoumarin D exhibited cytotoxic activity (IC₅₀ 65.6 µM).

A natural experiment study of the effects of imprisonment on violence in the community

One of the goals of imprisonment is to reduce violence¹. Although imprisonment has risen dramatically since the 1970s, its effects on future violent crime are poorly understood². This study's objective was to examine the effect of imprisonment on violent crime in the community among individuals on the policy margin between prison and probation sentences. Drawing on data from a population-based cohort of individuals convicted of a felony in Michigan between 2003 and 2006 (n = 111,110) and followed through June 2015, we compared the rates of commission of violent crime committed by individuals sentenced to prison with those of individuals sentenced to probation using a natural experiment based on the random assignment of judges to criminal cases. Being sentenced to prison had no significant effects on arrests or convictions for violent crimes after release from prison, but imprisonment modestly reduced the probability of violence if comparisons included the effects of incapacitation during imprisonment. These results suggest that for individuals on the current policy margin between prison and probation, imprisonment is an ineffective long-term intervention for violence prevention, as it has, on balance, no rehabilitative or deterrent effects after release.

Abrupt spin crossover in iron(iii) complexes with aromatic anions

Two iron(iii) complexes, [Fe(qsal-X)₂]OTs·nH₂O, are found to exhibit abrupt spin crossover with the spin transition temperature substituent dependent, and X⋯O halogen bonds linking the spin centres.

A simple flow injection spectrophotometric procedure for iron(III) determination using Phyllanthus emblica Linn. as a natural reagent

The use of natural reagents from plant extracts for chemical analysis is one approach in the development of green analytical chemistry methodology. In this work, a natural reagent extracted from Phyllanthus emblica Linn. has been applied for the determination of iron(III) using a simple flow injection spectrophotometric method. The method was based on the measurement of a dark-purple complex formed by the reaction between iron(III) and the extracted solution in an acetate buffer (pH 5.6) at 570 nm. Under the optimum conditions, a linear calibration graph in the range of 0.50-20.0 mg L^-1 iron(III) was obtained with a correlation coefficient (r²) of 0.9996. The limit of detection and limit of quantification were 0.31 and 0.50 mg L^-1, respectively. The relative standard deviation was less than 2.50%. The proposed method was successfully applied for quantitative analysis of iron(III) in pharmaceutical preparations and water samples with a sampling rate of 90 samples h^-1. The results are in good agreement with those obtained by the official ICP-OES technique at the 95% confidence level. The presented method provides a simple, cost-effective and environmentally friendly approach which is suitable and useful for determining iron(III). Therefore, it can be considered as an alternative analytical technique in green chemistry.

Self-assembly of a mixed-valence FeII–FeIII tetranuclear star

A self-assembled mixed-valence Fe^II–Fe^III tetranuclear star is reported that shows ferromagnetic coupling, field-induced single molecule magnetism and strong magnetic anisotropy at the peripheral Fe^II centres.

Slow relaxation of magnetization in a bis-mer-tridentate octahedral Co(ii) complex

A field-induced Co^II single-ion magnet is described. Supramolecular effects on magnetic anisotropy, and the relaxation mechanism are discussed.

Solvatomorphism and anion effects in predominantly low spin iron(iii) Schiff base complexes

The magnetic properties of a series of iron(iii) complexes [Fe(naphEen)₂]halide·sol are reported.

Custodial Parole Sanctions and Earnings after Release from Prison

Although the labor market consequences of incarceration in prison have been central to the literature on mass incarceration, punishment, and inequality, other components of the growing criminal justice system have received less attention from sociologists. In particular, the rise of mass incarceration was accompanied by an even larger increase in community supervision. In this paper, we examine the labor market effects of one frequently experienced aspect of post-prison parole, short-term custody for parole violations. Although such sanctions are viewed as an alternative to returning parole violators to prison, they have the potential to affect labor market outcomes in ways similar to imprisonment, including both adverse and positive effects on earnings. We estimate that parolees lost approximately 37 percent of their earnings in quarters during which they were in short-term custody. Although their earnings tended to increase in the quarter immediately following short-term custody-consistent with the stated intentions of such sanctions-parolees experienced further earnings loss over the longer term after such sanctions. In the third quarter following a short-term custody sanction, earnings are lowered by about 13 percent. These associations are larger for those who were employed in the formal labor market before their initial incarceration.

ICESat/GLAS Altimetry Measurements: Received Signal Dynamic Range and Saturation Correction

NASA's Ice, Cloud, and land Elevation Satellite (ICESat), which operated between 2003 and 2009, made the first satellite-based global lidar measurement of Earth's ice sheet elevations, sea-ice thickness and vegetation canopy structure. The primary instrument on ICESat was the Geoscience Laser Altimeter System (GLAS), which measured the distance from the spacecraft to Earth's surface via the roundtrip travel time of individual laser pulses. GLAS utilized pulsed lasers and a direct detection receiver consisting of a silicon avalanche photodiode (Si APD) and a waveform digitizer. Early in the mission, the peak power of the received signal from snow and ice surfaces was found to span a wider dynamic range than planned, often exceeding the linear dynamic range of the GLAS 1064-nm detector assembly. The resulting saturation of the receiver distorted the recorded signal and resulted in range biases as large as ~50 cm for ice and snow-covered surfaces. We developed a correction for this "saturation range bias" based on laboratory tests using a spare flight detector, and refined the correction by comparing GLAS elevation estimates to those derived from Global Positioning System (GPS) surveys over the calibration site at the salar de Uyuni, Bolivia. Applying the saturation correction largely eliminated the range bias due to receiver saturation for affected ICESat measurements over Uyuni and significantly reduced the discrepancies at orbit crossovers located on flat regions of the Antarctic ice sheet.

Trajectories of neighborhood attainment after prison

A potentially important but understudied aspect of prisoner reentry is the neighborhood environments experienced by formerly incarcerated people. We know that many formerly incarcerated people return to very disadvantaged neighborhood environments and that returning to disadvantaged neighborhoods after prison increases the risk of recidivism and reduces employment. Yet very little is known about the social, economic, and institutional processes that sort formerly incarcerated people into different neighborhoods after release or their trajectories of neighborhood attainment over time. Motivated by a conceptualization of prisoner reentry and reintegration as a process that unfolds over time, we examine trajectories of neighborhood environments after release. Motivated by the literature on neighborhood attainment, social capital, and the role of criminal justice institutions in structuring the lives of former prisoners, we examine sources of variation in neighborhood attainment. We use administrative data from the Michigan Department of Corrections on formerly incarcerated people paroled in 2003 and followed for two years after release. Descriptive results from a latent class trajectory model show that most white and black formerly incarcerated people experience flat trajectories, with little upward or downward residential mobility over time. Findings from multi-level growth curve models suggest that institutional factors are particularly important for the neighborhood attainment of whites, while human capital and social ties are particularly important for blacks. Among both blacks and whites, pre-prison and first post-prison neighborhood conditions exhibit a strong association with post-prison neighborhood attainment, although these associations are larger for blacks than whites.

Solvent modified spin crossover in an iron(iii) complex: phase changes and an exceptionally wide hysteresis

The impact of solvent on spin crossover is explored with T_1/2 varying by 200 K and hysteresis up to 80 K.

Solvent effects in a series of Fe(iii) spin crossover (SCO) complexes [Fe(qsal-I)₂]OTf·sol (sol = MeOH 1, EtOH 2, n-PrOH 3, i-PrOH 4, acetone 5 and MeCN 6) are explored. SCO is abrupt in 1 (following MeOH loss) and 2, gradual for 3 (T_1/2 = 199 K) and 4 (T_1/2 = 251 K) and incomplete, even up to 350 K, for 5 and 6. In [Fe(qsal-I)₂]OTf SCO occurs at T_1/2↓ = 225 K and T_1/2↑ = 234 K (ΔT = 9 K), while aged samples of 2 exhibit an exceptionally wide hysteresis of 80 K (T_1/2↓ = 139 K and T_1/2↑ = 219 K). In contrast, fresh samples of 2 exhibit stepped SCO with hysteresis varying from 2 to 42 K. VT-PXRD (variable temperature powder X-ray diffraction) studies indicate a new phase, 2b, is formed upon cooling below 180 K along with a minor LS phase 2c. Phase 2c and the HS phase 2a undergo a spin transition at T_1/2↓ = 180 K and T_1/2↑ = 215 K with phase 2b exhibiting two-step SCO. Structural studies in both spin states, except 6, show the cations are linked through extensive π–π interactions to form 1D chains. A combination of P4AE (parallel fourfold aryl embrace) and I···X (X = I, O, π) interactions create tightly packed 3D supramolecular networks. This study emphasizes that while solvent may result in only small structural changes SCO characteristics can be impacted dramatically.

Narrative change, narrative stability, and structural constraint: The case of prisoner reentry narratives

Cultural sociologists and other social scientists have increasingly used the concept of narrative as a theoretical tool to understand how individuals make sense of the links between their past, present, and future, how individuals construct social identities from cultural building blocks, and how culture shapes social action and individual behavior. Despite its richness, we contend that the narratives literature has yet to grapple with narrative change and stability when structural constraints or barriers challenge personal narratives and narrative identities. Particularly for marginalized groups, the potential incompatibility of personal narratives with daily experiences raises questions about the capacity of narratives to influence behavior and decision-making. In this study we draw on prospective longitudinal data on the reentry narratives and narrative identities of former prisoners to understand how narratives do and not change when confronted with contradictory experiences and structural constraints. We identify and describe the processes generating narrative change and stability among our subjects. These findings inform a framework for studying narrative change and stability based on four factors: the content of the narrative itself, the structural circumstances experienced by the individual, the institutional contexts in which the individual is embedded, and the social networks in which the individual is embedded.

Snow Grain Size Retrieval over the Polar Ice Sheets with the Ice, Cloud, and land Elevation Satellite (ICESat) Observations

Snow grain size is an important parameter for cryosphere studies. As a proof of concept, this paper presents an approach to retrieve this parameter over Greenland, East and West Antarctica ice sheets from surface reflectances observed with the Geoscience Laser Altimeter System (GLAS) onboard the Ice, Cloud, and land Elevation Satellite (ICESat) at 1064 nm. Spaceborne lidar observations overcome many of the disadvantages in passive remote sensing, including difficulties in cloud screening and low sun angle limitations; hence tend to provide more accurate and stable retrievals. Results from the GLAS L2A campaign, which began on 25 September and lasted until 19 November, 2003, show that the mode of the grain size distribution over Greenland is the largest (~300 μm) among the three, West Antarctica is the second (~220 μm) and East Antarctica is the smallest (~190 μm). Snow grain sizes are larger over the coastal regions compared to inland the ice sheets. These results are consistent with previous studies. Applying the broadband snow surface albedo parameterization scheme developed by Garder and Sharp (2010) to the retrieved snow grain size, ice sheet surface albedo is also derived. In the future, more accurate retrievals can be achieved with multiple wavelengths lidar observations.

Hysteretic spin crossover driven by anion conformational change

An air stable Fe^III complex showing a wide hysteresis near room temperature is described. The origin of the cooperativity is an unprecedented anion conformational change.

Spin crossover in mixed ligand iron(iii) complexes

The use of two subtly different ligands is used to explore their impact on spin crossover characteristics.

Automatic Image Registration of Multi-Modal Remotely Sensed Data with Global Shearlet Features

Automatic image registration is the process of aligning two or more images of approximately the same scene with minimal human assistance. Wavelet-based automatic registration methods are standard, but sometimes are not robust to the choice of initial conditions. That is, if the images to be registered are too far apart relative to the initial guess of the algorithm, the registration algorithm does not converge or has poor accuracy, and is thus not robust. These problems occur because wavelet techniques primarily identify isotropic textural features and are less effective at identifying linear and curvilinear edge features. We integrate the recently developed mathematical construction of shearlets, which is more effective at identifying sparse anisotropic edges, with an existing automatic wavelet-based registration algorithm. Our shearlet features algorithm produces more distinct features than wavelet features algorithms; the separation of edges from textures is even stronger than with wavelets. Our algorithm computes shearlet and wavelet features for the images to be registered, then performs least squares minimization on these features to compute a registration transformation. Our algorithm is two-staged and multiresolution in nature. First, a cascade of shearlet features is used to provide a robust, though approximate, registration. This is then refined by registering with a cascade of wavelet features. Experiments across a variety of image classes show an improved robustness to initial conditions, when compared to wavelet features alone.

Neighborhood Effect Heterogeneity by Family Income and Developmental Period

Effects of disadvantaged neighborhoods on child educational outcomes likely depend on a family's economic resources and the timing of neighborhood exposures during the course of child development. This study investigates how timing of exposure to disadvantaged neighborhoods during childhood versus adolescence affects high school graduation and whether these effects vary across families with different income levels. It follows 6,137 children in the PSID from childhood through adolescence and overcomes methodological problems associated with the joint endogeneity of neighborhood context and family income by adapting novel counterfactual methods--a structural nested mean model estimated via two-stage regression with residuals--for time-varying treatments and time-varying effect moderators. Results indicate that exposure to disadvantaged neighborhoods, particularly during adolescence, has a strong negative effect on high school graduation and that this negative effect is more severe for children from poor families.

Homelessness and Housing Insecurity Among Former Prisoners

The United States has experienced dramatic increases in both incarceration rates and the population of insecurely housed or homeless persons since the 1980s. These marginalized populations have strong overlaps, with many people being poor, minority, and from an urban area. That a relationship between homelessness, housing insecurity, and incarceration exists is clear, but the extent and nature of this relationship is not yet adequately understood. We use longitudinal, administrative data on Michigan parolees released in 2003 to examine returning prisoners' experiences with housing insecurity and homelessness. Our analysis finds relatively low rates of outright homelessness among former prisoners, but very high rates of housing insecurity, much of which is linked to features of community supervision, such as intermediate sanctions, returns to prison, and absconding. We identify risk factors for housing insecurity, including mental illness, substance use, prior incarceration, and homelessness, as well as protective "buffers" against insecurity and homelessness, including earnings and social supports.