Evidence for Astrophysical Muon Neutrinos from the Northern Sky with IceCube

Results from the IceCube Neutrino Observatory have recently provided compelling evidence for the existence of a high energy astrophysical neutrino flux utilizing a dominantly Southern Hemisphere data set consisting primarily of ν(e) and ν(τ) charged-current and neutral-current (cascade) neutrino interactions. In the analysis presented here, a data sample of approximately 35,000 muon neutrinos from the Northern sky is extracted from data taken during 659.5 days of live time recorded between May 2010 and May 2012. While this sample is composed primarily of neutrinos produced by cosmic ray interactions in Earth's atmosphere, the highest energy events are inconsistent with a hypothesis of solely terrestrial origin at 3.7σ significance. These neutrinos can, however, be explained by an astrophysical flux per neutrino flavor at a level of Φ(E(ν))=9.9(-3.4)(+3.9)×10(-19)  GeV(-1) cm(-2) sr(-1) s(-1)(E(ν)/100  TeV(-2), consistent with IceCube's Southern-Hemisphere-dominated result. Additionally, a fit for an astrophysical flux with an arbitrary spectral index is performed. We find a spectral index of 2.2(-0.2)(+0.2), which is also in good agreement with the Southern Hemisphere result.

Diet- and Genetically-Induced Obesity Differentially Affect the Fecal Microbiome and Metabolome in Apc1638N Mice

Obesity is a risk factor for colorectal cancer (CRC), and alterations in the colonic microbiome and metabolome may be mechanistically involved in this relationship. The relative contribution of diet and obesity per se are unclear. We compared the effect of diet- and genetically-induced obesity on the intestinal microbiome and metabolome in a mouse model of CRC. Apc1638N mice were made obese by either high fat (HF) feeding or the presence of the Leprdb/db (DbDb) mutation. Intestinal tumors were quantified and stool microbiome and metabolome were profiled. Genetic obesity, and to a lesser extent HF feeding, promoted intestinal tumorigenesis. Each induced distinct microbial patterns: taxa enriched in HF were mostly Firmicutes (6 of 8) while those enriched in DbDb were split between Firmicutes (7 of 12) and Proteobacteria (5 of 12). Parabecteroides distasonis was lower in tumor-bearing mice and its abundance was inversely associated with colonic Il1b production (p<0.05). HF and genetic obesity altered the abundance of 49 and 40 fecal metabolites respectively, with 5 in common. Of these 5, adenosine was also lower in obese and in tumor-bearing mice (p<0.05) and its concentration was inversely associated with colonic Il1b and Tnf production (p<0.05). HF and genetic obesity differentially alter the intestinal microbiome and metabolome. A depletion of adenosine and P.distasonis in tumor-bearing mice could play a mechanistic role in tumor formation. Adenosine and P. distasonis have previously been shown to be anti-inflammatory in the colon and we postulate their reduction could promote tumorigenesis by de-repressing inflammation.

Polymorphisms in maternal folate pathway genes interact with arsenic in drinking water to influence risk of myelomeningocele

BACKGROUND

Arsenic induces neural tube defects in many animal models. Additionally, studies have shown that mice with specific genetic defects in folate metabolism and transport are more susceptible to arsenic-induced neural tube defects. We sought to determine whether 14 single-nucleotide polymorphisms in genes involved in folate metabolism modified the effect of exposure to drinking water contaminated with inorganic arsenic and posterior neural tube defect (myelomeningocele) risk.

METHODS

Fifty-four mothers of children with myelomeningocele and 55 controls were enrolled through clinical sites in rural Bangladesh in a case-control study of the association between environmental arsenic exposure and risk of myelomeningocele. We assessed participants for level of myelomeningocele, administered questionnaires, conducted biological and environmental sample collection, and performed genotyping. Inductively coupled plasma mass spectrometry was used to measure inorganic arsenic concentration in drinking water. Candidate single-nucleotide polymorphisms were identified through review of the literature.

RESULTS

Drinking water inorganic arsenic concentration was associated with increased risk of myelomeningocele for participants with 4 of the 14 studied single-nucleotide polymorphisms in genes involved in folate metabolism: the AA/AG genotype of rs2236225 (MTHFD1), the GG genotype of rs1051266 (SLC19A1), the TT genotype of rs7560488 (DNMT3A), and the GG genotype of rs3740393 (AS3MT) with adjusted odds ratio of 1.13, 1.31, 1.20, and 1.25 for rs2236225, rs1051266, rs7560488, and rs3740393, respectively.

CONCLUSION

Our results support the hypothesis that environmental arsenic exposure increases the risk of myelomeningocele by means of interaction with folate metabolic pathways.

Flavor Ratio of Astrophysical Neutrinos above 35 TeV in IceCube

A diffuse flux of astrophysical neutrinos above 100 TeV has been observed at the IceCube Neutrino Observatory. Here we extend this analysis to probe the astrophysical flux down to 35 TeV and analyze its flavor composition by classifying events as showers or tracks. Taking advantage of lower atmospheric backgrounds for showerlike events, we obtain a shower-biased sample containing 129 showers and 8 tracks collected in three years from 2010 to 2013. We demonstrate consistency with the (fe:fμ:fτ)⊕≈(1:1:1)⊕ flavor ratio at Earth commonly expected from the averaged oscillations of neutrinos produced by pion decay in distant astrophysical sources. Limits are placed on nonstandard flavor compositions that cannot be produced by averaged neutrino oscillations but could arise in exotic physics scenarios. A maximally tracklike composition of (0:1:0)⊕ is excluded at 3.3σ, and a purely showerlike composition of (1:0:0)⊕ is excluded at 2.3σ.

Arsenic is associated with reduced effect of folic acid in myelomeningocele prevention: a case control study in Bangladesh

BACKGROUND

Arsenic induces neural tube defects in several animal models, but its potential to cause neural tube defects in humans is unknown. Our objective was to investigate the associations between maternal arsenic exposure, periconceptional folic acid supplementation, and risk of posterior neural tube defect (myelomeningocele) among a highly exposed population in rural Bangladesh.

METHODS

We performed a case-control study that recruited physician-confirmed cases from community health clinics served by Dhaka Community Hospital in Bangladesh, as well as local health facilities that treat children with myelomeningocele. Controls were selected from pregnancy registries in the same areas. Maternal arsenic exposure was estimated from drinking water samples taken from wells used during the first trimester of pregnancy. Periconceptional folic acid use was ascertained by self-report, and maternal folate status was further assessed by plasma folate levels measured at the time of the study visit.

RESULTS

Fifty-seven cases of myelomeningocele were identified along with 55 controls. A significant interaction was observed between drinking water inorganic arsenic and periconceptional folic acid use. As drinking water inorganic arsenic concentrations increased from 1 to 25 μg/L, the estimated protective effect of folic acid use declined (OR 0.22 to 1.03), and was not protective at higher concentrations of arsenic. No main effect of arsenic exposure on myelomeningocele risk was identified.

CONCLUSIONS

Our study found a significant interaction between drinking water inorganic arsenic concentration from wells used during the first trimester of pregnancy and reported intake of periconceptional folic acid supplements. Results suggest that environmental arsenic exposure reduces the effectiveness of folic acid supplementation in preventing myelomeningocele.

The impact of walking speed on the effects of functional electrical stimulation for foot drop in people with multiple sclerosis

PURPOSE

Functional electrical stimulation (FES) is effective in assisting people with multiple sclerosis (pwMS) with gait. Previous studies have investigated the effects of FES in pwMS with slow self-selected walking speeds (SSWS). This study reports on the effect of the Odstock Dropped Foot Stimulator (ODFS) on the speed and oxygen (O2) cost of gait in pwMS walking at a range of SSWS.

METHODS

Twenty pwMS (mean age 50.4 ± 7.3 years) currently using FES walked at their SSWS for 5 min with and without FES. O2 cost of gait was measured using a gas analysis system, and gait speed was calculated. Data were analysed for all participants, and comparisons were made between those with a SSWS < and >0.8 m/s (walking speed required for community ambulation).

RESULTS

Significant improvements in the speed and O2 cost of gait were seen using FES in the group with SSWS <0.8 m/s (n = 11, p = 0.005). When participants' SSWS >0.8 m/s, no difference in gait speed was noted, and a significant increase in O2 cost of gait using FES (n = 9, p = 0.004) was noted.

CONCLUSION

FES has a different effect on the speed and O2 cost of gait dependent on the SSWS of pwMS. This requires further investigation. Implications for Rehabilitation Functional electrical stimulation (FES) used for foot drop is effective in improving the speed and oxygen cost of walking in pwMS walking at SSWS <0.8 m/s. FES does not seem to have a beneficial effect on the speed and oxygen cost of walking in pwMS walking at SSWS >0.8 m/s. Further research is needed to understand the possible mechanisms involved so that FES for foot drop can be efficiently prescribed.

Development of a general analysis and unfolding scheme and its application to measure the energy spectrum of atmospheric neutrinos with IceCube: IceCube Collaboration

We present the development and application of a generic analysis scheme for the measurement of neutrino spectra with the IceCube detector. This scheme is based on regularized unfolding, preceded by an event selection which uses a Minimum Redundancy Maximum Relevance algorithm to select the relevant variables and a random forest for the classification of events. The analysis has been developed using IceCube data from the 59-string configuration of the detector. 27,771 neutrino candidates were detected in 346 days of livetime. A rejection of 99.9999 % of the atmospheric muon background is achieved. The energy spectrum of the atmospheric neutrino flux is obtained using the TRUEE unfolding program. The unfolded spectrum of atmospheric muon neutrinos covers an energy range from 100 GeV to 1 PeV. Compared to the previous measurement using the detector in the 40-string configuration, the analysis presented here, extends the upper end of the atmospheric neutrino spectrum by more than a factor of two, reaching an energy region that has not been previously accessed by spectral measurements.

Observation of high-energy astrophysical neutrinos in three years of IceCube data

A search for high-energy neutrinos interacting within the IceCube detector between 2010 and 2012 provided the first evidence for a high-energy neutrino flux of extraterrestrial origin. Results from an analysis using the same methods with a third year (2012-2013) of data from the complete IceCube detector are consistent with the previously reported astrophysical flux in the 100 TeV-PeV range at the level of 10(-8)  GeV cm-2 s-1 sr-1 per flavor and reject a purely atmospheric explanation for the combined three-year data at 5.7σ. The data are consistent with expectations for equal fluxes of all three neutrino flavors and with isotropic arrival directions, suggesting either numerous or spatially extended sources. The three-year data set, with a live time of 988 days, contains a total of 37 neutrino candidate events with deposited energies ranging from 30 to 2000 TeV. The 2000-TeV event is the highest-energy neutrino interaction ever observed.

Evidence for high-energy extraterrestrial neutrinos at the IceCube detector

We report on results of an all-sky search for high-energy neutrino events interacting within the IceCube neutrino detector conducted between May 2010 and May 2012. The search follows up on the previous detection of two PeV neutrino events, with improved sensitivity and extended energy coverage down to about 30 TeV. Twenty-six additional events were observed, substantially more than expected from atmospheric backgrounds. Combined, both searches reject a purely atmospheric origin for the 28 events at the 4σ level. These 28 events, which include the highest energy neutrinos ever observed, have flavors, directions, and energies inconsistent with those expected from the atmospheric muon and neutrino backgrounds. These properties are, however, consistent with generic predictions for an additional component of extraterrestrial origin.

Abstract PD5-6: Sustained hyperactivated mTOR & JAK2/STAT3 pathways in inflammatory breast cancer (IBC): Evidence for mTOR plus JAK2 therapeutic targeting

Background: IBC is an aggressive form of breast cancer with poor prognosis. Combined multi-modality therapy results in a 5 year OS of 30%, underscoring the unmet need for targeted therapy. Our preclinical research in cell lines & xenograft tumor models has identified a role for hyper-activated PI3K/mTOR signaling in IBC. IBC cells express IL-6 and IL-8, which recruit tumor activated macrophages (TAMs) that further induce inflammatory cytokines and activate the JAK2/STAT3 pathway. We investigated the independent and combined activity of these pathways in IBC patient tissues.

Methods: Archived tissue specimens of 42 IBC patients (dx 1999-2009) and 27 non-IBC patients (dx 2001-2005) with invasive ductal carcinoma (IDC) were obtained. Surrounding non-tumor normal tissue from IBC (companion controls) was also utilized. All specimens were analyzed using immunohistochemistry (IHC) and scored by 3 independent pathologists. Results were defined as 0 = negative; 1+,2+ = positive for activated mTOR (P-S6); activated JAK2/STAT3 (P-JAK2; P-STAT3); cytokine (IL-6); macrophage infiltration (CD68) and TAM (CD163). Proportions of IBC cases with positive expression were compared with non-IBC cases (Fisher's exact test) & companion controls (McNemar's test). Clinical & survival data were obtained.

Results: Median age at diagnosis: 46 yrs (31-62) in early stage IBC [EIBC] (n = 37) & 41 yrs (29-57) in pts with de novo metastatic IBC [MIBC] (n = 5). In EIBC, 19/36: HER2+ (1 unk); 8/19: ER+/HER2+; 8/36: ER-/HER2-. In MIBC, all were ER- (1 unk) & 3/4 were HER2+ (1 unk). 88% were rx with neoadjuvant &/or adjuvant anthracycline & taxane w/o adjuvant trastuzumab. There were 24 pt deaths (5/5 MIBC). Median f/u for EIBC: 6.3 yrs and for MIBC: 3.4 yrs. Median OS: 81.4 mo (95% CI lower 48 mo) for EIBC & 41 mo (95% CI 8-81 mo) for MIBC. Median RFS: 18 mo (95% CI 18-79 mo) for 23 pts (13 NED; 1 unk). The non-IBC patients were all stage 2-3 with median age at diagnosis: 58 yrs (39-94). 19/27: ER+; 7/25 HER2+ (2 unk); 15/25 ER+/HER2-; 3/25 ER-/HER2-. 78% were rx with adjuvant anthracycline & taxane, 4% were rx with FEC and 18% did not receive adjuvant chemotherapy. 18% received adjuvant trastuzumab. Median f/u: 8.0 yrs. Median OS: not yet reached and median RFS: 111.3 mo (95% CI lower 34.5 mo). EIBC cases were compared with non-IBC cases & companion controls (Table 1). PS6, pJAK2 and pSTAT3 expression was significantly increased in IBC compared to non-IBC. Of the 29 EIBC patients with complete biomarker data who were PS6+, 28/29 (97%) were JAK2+, 15/29 (52%) were STAT3+, 26/29 (90%) were CD68+, 20/29 (69%) were CD163+ and 28/29 (97%) were IL6+.

Conclusion: This is the first study to validate preclinical findings & show a strong co-association between hyper-activation of mTOR & JAK/STAT pathways in most IBC patient tumors when compared to surrounding non-tumor tissue and non-IBC (IDC) tumors and tissues. These findings suggest a key role for dual blockade of mTOR & JAK/STAT pathways for IBC in phase I trials.

BiomarkerMcNemars p-value: Early Stage IBC vs companion controls (N = 37)Fishers p-value: Early stage IBC (N = 37)vs non-IBC (N = 27)PS6&lt;0.00010.0315pJAK2&lt;0.0001&lt;0.0001pSTAT30.0003&lt;0.0001CD163&lt;0.00010.0908CD68&lt;0.00010.0582IL60.00030.3882

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr PD5-6.

Measurement of atmospheric neutrino oscillations with IceCube

We present the first statistically significant detection of neutrino oscillations in the high-energy regime (>20 GeV) from an analysis of IceCube Neutrino Observatory data collected in 2010 and 2011. This measurement is made possible by the low-energy threshold of the DeepCore detector (~20 GeV) and benefits from the use of the IceCube detector as a veto against cosmic-ray-induced muon background. The oscillation signal was detected within a low-energy muon neutrino sample (20-100 GeV) extracted from data collected by DeepCore. A high-energy muon neutrino sample (100 GeV-10 TeV) was extracted from IceCube data to constrain systematic uncertainties. The disappearance of low-energy upward-going muon neutrinos was observed, and the nonoscillation hypothesis is rejected with more than 5σ significance. In a two-neutrino flavor formalism, our data are best described by the atmospheric neutrino oscillation parameters |Δm(32)(2)|=(2.3(-0.5)(+0.6))×10(-3) eV(2) and sin(2)(2θ(23))>0.93, and maximum mixing is favored.