Evaluation of food security status, psychological well-being, and stress on BMI and diet-related behaviors among a sample of college students

OBJECTIVES

The purpose of this study was to evaluate food insecurity on body mass index (BMI) and diet-related behaviors among college students and whether psychological well-being (PWB) and stress levels mediate this relationship.

STUDY DESIGN

This was a cross-sectional study.

METHODS

Data from 1439 students from the American College Health Association National College Health Assessment III (Fall 2020) were used. Food security status was evaluated by the USDA Six-Item Short Form. PWB was measured using the Diener Flourishing Scale. Diet-related behaviors included the average servings of fruits, vegetables, and sugar-sweetened beverages consumed per day. Stress was measured by self-reported levels. Regression model analysis evaluated the influence of food security status, PWB, and stress levels on BMI. PWB and stress were also tested as mediators in the relationship between food insecurity and BMI.

RESULTS

Among our sample of college students, 44.54% (n = 641) were food insecure, and 55.46% (n = 798) were food secure. Multiple regression analysis showed that higher food insecurity, older age, full-time enrollment status, and fifth-year student status were positively associated with a higher BMI score (P < 0.05). Results from mediation models revealed that PWB, but not stress, mediated the relationship between food security and BMI among Black/African American students. Regarding diet-related behaviors, high stress levels mediated the relationship between food insecurity and sugar-sweetened beverage intake among students.

CONCLUSIONS

Food insecurity appears to influence BMI in college students. This relationship seems to be mediated by disrupted PWB and a higher intake of sugar-sweetened beverages due to stress.

The post-conflict expansion of coca farming and illicit cattle ranching in Colombia

Illicit cattle ranching and coca farming have serious negative consequences on the Colombian Amazon's land systems. The underlying causes of these land activities include historical processes of colonization, armed conflict, and narco-trafficking. We aim to examine how illicit cattle ranching and coca farming are driving forest cover change over the last 34 years (1985-2019). To achieve this aim, we combine two pixel-based approaches to differentiate between coca farming and cattle ranching using hypothetical observed patterns of illicit activities and a deep learning algorithm. We found evidence that cattle ranching, not coca, is the main driver of forest loss outside the legal agricultural frontier. There is evidence of a recent, explosive conversion of forests to cattle ranching outside the agricultural frontier and within protected areas since the negotiation phase of the peace agreement. In contrast, coca is remarkably persistent, suggesting that crop substitution programs have been ineffective at stopping the expansion of coca farming deeper into protected areas. Countering common narratives, we found very little evidence that coca farming precedes cattle ranching. The spatiotemporal dynamics of the expansion of illicit land uses reflect the cumulative outcome of agrarian policies, Colombia's War on Drugs, and the 2016 peace accord. Our study enables the differentiation of illicit land activities, which can be transferred to other regions where these activities have been documented but poorly distinguished spatiotemporally. We provide an applied framework that could be used elsewhere to disentangle other illicit land uses, track their causes, and develop management options for forested land systems and people who depend on them.

Penumbra: A spatially distributed, mechanistic model for simulating ground-level incident solar energy across heterogeneous landscapes

Landscape solar energy is a significant environmental driver, yet it remains complicated to model well. Several solar radiation models simplify the complexity of light by estimating it at discrete point locations or by averaging values over larger areas. These modeling approaches may be useful in certain cases, but they are unable to provide spatially distributed and temporally dynamic representations of solar energy across entire landscapes. We created a landscape-scale ground-level shade and solar energy model called Penumbra to address this deficiency. Penumbra simulates spatially distributed ground-level shade and incident solar energy at user-defined timescales by modeling local and distant topographic shading and vegetative shading. Spatially resolved inputs of a digital elevation model, a normalized digital surface model, and landscape object transmittance are used to estimate spatial variations in solar energy at user-defined temporal timesteps. The research goals for Penumbra included: 1) simulations of spatiotemporal variations of shade and solar energy caused by both objects and topographic features, 2) minimal user burden and parameterization, 3) flexible user defined temporal parameters, and 4) flexible external model coupling. We test Penumbra's predictive skill by comparing the model's predictions with monitored open and forested sites, and achieve calibrated mean errors ranging from -17.3 to 148.1 μmoles/m2/s. Penumbra is a dynamic model that can produce spatial and temporal representations of shade percentage and ground-level solar energy. Outputs from Penumbra can be used with other ecological models to better understand the health and resilience of aquatic, near stream terrestrial, and upland ecosystems.

Multiscale divergence between Landsat- and lidar-based biomass mapping is related to regional variation in canopy cover and composition

BACKGROUND

Satellite-based aboveground forest biomass maps commonly form the basis of forest biomass and carbon stock mapping and monitoring, but biomass maps likely vary in performance by region and as a function of spatial scale of aggregation. Assessing such variability is not possible with spatially-sparse vegetation plot networks. In the current study, our objective was to determine whether high-resolution lidar-based and moderate-resolution Landsat-base aboveground live forest biomass maps converged on similar predictions at stand- to landscape-levels (10 s to 100 s ha) and whether such differences depended on biophysical setting. Specifically, we examined deviations between lidar- and Landsat-based biomass mapping methods across scales and ecoregions using a measure of error (normalized root mean square deviation), a measure of the unsystematic deviations, or noise (Pearson correlation coefficient), and two measures related to systematic deviations, or biases (intercept and slope of a regression between the two sets of predictions).

RESULTS

Compared to forest inventory data (0.81-ha aggregate-level), lidar and Landsat-based mean biomass predictions exhibited similar performance, though lidar predictions exhibited less normalized root mean square deviation than Landsat when compared with the reference plot data. Across aggregate-levels, the intercepts and slopes of regression equations describing the relationships between lidar- and Landsat-based biomass predictions stabilized (i.e., little additional change with increasing area of aggregates) at aggregate-levels between 10 and 100 ha, suggesting a consistent relationship between the two maps at landscape-scales. Differences between lidar- and Landsat-based biomass maps varied as a function of forest canopy heterogeneity and composition, with systematic deviations (regression intercepts) increasing with mean canopy cover and hardwood proportion within forests and correlations decreasing with hardwood proportion.

CONCLUSIONS

Deviations between lidar- and Landsat-based maps indicated that satellite-based approaches may represent general gradients in forest biomass. Ecoregion impacted deviations between lidar and Landsat biomass maps, highlighting the importance of biophysical setting in determining biomass map performance across aggregate scales. Therefore, regardless of the source of remote sensing (e.g., Landsat vs. lidar), factors affecting the measurement and prediction of forest biomass, such as species composition, need to be taken into account whether one is estimating biomass at the plot, stand, or landscape scale.

Improved Soil Temperature Modeling Using Spatially Explicit Solar Energy Drivers

Modeling the spatial and temporal dynamics of soil temperature is deterministically complex due to the wide variability of several influential environmental variables, including soil column composition, soil moisture, air temperature, and solar energy. Landscape incident solar radiation is a significant environmental driver that affects both air temperature and ground-level soil energy loading; therefore, inclusion of solar energy is important for generating accurate representations of soil temperature. We used the U.S. Environmental Protection Agency's Oregon Crest-to-Coast (O'CCMoN) Environmental Monitoring Transect dataset to develop and test the inclusion of ground-level solar energy driver data within an existing soil temperature model currently utilized within an ecohydrology model called Visualizing Ecosystem Land Management Assessments (VELMA). The O'CCMoN site data elucidate how localized ground-level solar energy between open and forested landscapes greatly influence the resulting soil temperature. We demonstrate how the inclusion of local ground-level solar energy significantly improves the ability to deterministically model soil temperature at two depths. These results suggest that landscape and watershed-scale models should incorporate spatially distributed solar energy to improve spatial and temporal simulations of soil temperature.

Effects of harvest, fire, and pest/pathogen disturbances on the West Cascades ecoregion carbon balance

BACKGROUND

Disturbance is a key influence on forest carbon dynamics, but the complexity of spatial and temporal patterns in forest disturbance makes it difficult to quantify their impacts on carbon flux over broad spatial domains. Here we used a time series of Landsat remote sensing images and a climate-driven carbon cycle process model to evaluate carbon fluxes at the ecoregion scale in western Oregon.

RESULTS

Thirteen percent of total forest area in the West Cascades ecoregion was disturbed during the reference interval (1991-2010). The disturbance regime was dominated by harvesting (59 % of all area disturbed), with lower levels of fire (23 %), and pest/pathogen mortality (18 %). Ecoregion total Net Ecosystem Production was positive (a carbon sink) in all years, with greater carbon uptake in relatively cool years. Localized carbon source areas were associated with recent harvests and fire. Net Ecosystem Exchange (including direct fire emissions) showed greater interannual variation and became negative (a source) in the highest fire years. Net Ecosystem Carbon Balance (i.e. change in carbon stocks) was more positive on public that private forestland, because of a lower disturbance rate, and more positive in the decade of the 1990s than in the warmer and drier 2000s because of lower net ecosystem production and higher direct fire emissions in the 2000s.

CONCLUSION

Despite recurrent disturbances, the West Cascades ecoregion has maintained a positive carbon balance in recent decades. The high degree of spatial and temporal resolution in these simulations permits improved attribution of regional carbon sources and sinks.

Adolescent depression: Why more girls?

Although there has been evidence for some time of a sex difference in depression, relatively little research has examined the developmental process by which women come to be at greater risk than men for depression. In this paper, the developmental pattern of depressed affect is examined over early and middle adolescence, with a special focus on the patterns of boys as compared to girls. In addition, a developmental model for mental health in adolescence is tested for its power in explaining the emergence of gender differences in depression. Longitudinal data on 335 adolescents randomly selected from two school districts were used to test the hypotheses. Results revealed that girls are at risk for developing depressed affect by 12th grade because they experienced more challenges in early adolescence than did boys. The sex difference in depressed affect at 12th grade disappears once early adolescent challenges are considered.

High-peak-power femtosecond pulse compression with polarization-maintaining ytterbium-doped fiber amplification

We report the generation of 140 fs pulses with a peak power of up to 270 kW using a fiber pulse source based on a polarization-maintaining ytterbium-doped fiber amplifier and a semiconductor saturable absorber mirror mode-locked fiber laser seed. The seed laser pulses were amplified and chirped in the fiber amplifier and subsequently compressed in an external transmission grating pair. The use of a polarization-maintaining amplifier addresses nonlinear polarization-induced limitations to the obtainable compressed pulse duration and quality that can arise if isotropic fiber amplification is used. Numerical simulations of the system support the experimental measurements and also confirm the role of fiber dispersion in obtaining high-quality compressed pulses.

Ytterbium gain band self-induced modulation instability laser

We demonstrate an ytterbium gain band self-induced modulation instability laser. A highly nonlinear holey fiber is used to provide the anomalous dispersion required for bright soliton generation at 1 microm. The all-fiber integrated source yields a 40 GHz train of 4 ps pulses at a wavelength of 1064 nm.

Extended continuous-wave supercontinuum generation in a low-water-loss holey fiber

We report on the development of a 2.5 microm core photonic crystal fiber with a substantially reduced water-peak loss around 1.38 microm, which allows extended Raman-soliton supercontinuum generation up to 1.55 microm with a cw ytterbium fiber laser pump source. The resulting broadband, high-spectral-power-density, low-coherence light source can be employed for advanced, submicrometer resolution optical coherence tomography.

20-kW peak power all-fiber 1.57-microm source based on compression in air-core photonic bandgap fiber, its frequency doubling, and broadband generation from 430 to 1450 nm

We demonstrate an ultrashort all-fiber-integrated chirped-pulse amplification system yielding 1-ps pulses with 20 kW of peak power. 40-ps initial pulses generated by an externally modulated laser diode are chirped by self-phase modulation in a conventional fiber, amplified, and compressed in 110 m of air-core photonic bandgap fiber. The compressed pulses are frequency doubled in a periodically poled KTP crystal with up to 48% efficiency and applied to supercontinuum generation in a holey fiber, resulting in a high-power uniform continuum that stretches from 430 to 1450 nm.

Choline acetyltransferase expression studied with an oligonucleotide probe

1. The localization of choline acetyltransferase messenger RNA has been studied using a digoxigenin-tailed complementary oligodeoxynucleotide probe for in situ hybridization. 2. Putative cholinergic cells of the rat and ferret spinal cord and the ferret retina were labeled. 3. This technique affords superior resolution compared to radioactively labeled probes, with apparently equal sensitivity.

Strabismus caused by melanoma metastatic to an extraocular muscle

Nonocular melanoma rarely metastasizes to the orbit. We report the case of a melanoma presumably arising from an axillary lymph node sinus that metastasized to the left medial rectus muscle causing proptosis, diplopia, and reduced saccadic velocity measurements. Clinical, radiographic, and histopathologic data are presented and discussed.

Simultaneous aortic reconstruction and bilateral renal revascularization. Is this a safe and effective procedure?

Between 1982 and 1987, 32 patients with severe aortorenal atherosclerosis had simultaneous aortic and bilateral renal revascularization. All patients were hypertensive. Eighteen patients (56%) had renal insufficiency with a mean serum creatinine (SC) of 2.8 mg/dl. Nine patients had an aortic aneurysm; the remaining 23 patients had aortoiliac occlusive disease of varying severity. Aortic reconstruction was done with either a straight (six patients) or bifurcated (26 patients) Dacron graft. Renal revascularization was accomplished with either bypass (60 arteries) or transaortic endarterectomy (four arteries). One patient died of pulmonary embolism (operative mortality rate 3%). Beneficial blood pressure response was achieved in 28 of 31 survivors, (90%). Among the 18 patients with renal insufficiency, mean SC was 2.80 +/- 1.18 mg/dl preoperatively and 1.65 +/- 0.48 mg/dl postoperatively (p less than 0.001). Among eight patients with severe renal dysfunction before surgery (SC greater than 3 mg/dl), mean SC was 3.90 +/- 0.85 mg/dl before and 1.79 +/- 0.69 mg/dl after operation (p less than 0.001). In follow-up extending to 58 months (mean 27.6 months), five late deaths occurred; cumulative survival was 94% at 2 years and 60% at 4 years. There were no instances of worsening hypertension; one patient had deteriorating renal function. These results indicate that severe aortorenal atherosclerosis can be managed with simultaneous aortic reconstruction and bilateral renal revascularization at low operative risk. In addition, there can be high expectation of significant and persisting benefit in both hypertension and renal dysfunction after operation.

The orbital surgeon

While the number of orbital surgeons is limited, it is hoped these can be recognized and patients referred to them by ophthalmologists not interested or trained in that specialty. Let the orbital surgeon determine whether he can handle the problem in 1 to 2 days, or whether a neurosurgeon should do the procedure or make it a joint effort. It may well involve other specialty team effort approaches. It is essential to have an understanding of x-rays, CT, angiography, and MRI techniques and films. Sit with these specialists to learn more and help to avoid negative, misdiagnosis reports in the interest of the patient. Use judgement in helping the patient decide on ophthalmic or the more extensive neurosurgical approach after careful study and what is in their best interest. The team approach is used in well established medical centers with the ophthalmologist and neurosurgeon (or other specialist) working together in the best interest of the patient. This is more interesting and keeps the ophthalmologist in the mainstream of medicine.

An evaluation of 820 orbital cases

Eight hundred twenty clinical orbital cases have been reviewed as seen over a 34-year period. These are tabulated as to classification, numbers, and percentages. They include biopsy-proven (450 cases) and other clinical cases. These are patients seen by ophthalmologists practicing in an average community area rather than a large referral center and thus may be more truly representative of what might be encountered in practice. Any series has a certain bias. The advantage of a biopsy-proven series is recognized for the certainty and prognostic aspect. A clinical series represents a wider practical correlation and may include cases not likely to be biopsied, such as hemangioma. It is hoped that the percentage figures of these types of cases will help the clinician in his diagnostic evaluation of patients with orbital lesions. In this series 34% of the orbital lesions were malignant which warrants an aggressive approach for such cases rather than conservative supervision. Because of the very limited number or absence of some types of cases even in a large clinical or biopsy-proven series, I feel it warrants the development of a standard classification of lesions to be used by everyone. Also, assembling the data on infrequent types of lesions from a number of medical centers would give a much larger series and would have a more meaningful prognostic significance. This might be accomplished through one of our national ophthalmologic societies.

Pulsating exophthalmos: orbital tumors in siblings

The extremely rare occurrence of sibling brothers with left pulsating exophthalmos has been presented with very similar plain film and CT scan findings. Other patients presented demonstrate the strong familial trend of neurofibromatosis, the multiplicity of lesions, the progression of lesions. Genetic counseling is indicated, together with educating the patient and family as to further neurologic deficits which may develop. On-going evaluation at intervals is indicated. Significant cases should only be approached surgically with the realization of the seriousness of what both the patient and doctor may encounter. Surgery, unfortunately, usually cannot offer much help. An interdisciplinary approach with the surgeon, plastic surgeon, neurosurgeon, and ophthalmologist offers a safer approach.

Indications and surgical techniques for orbital exenteration

Indications for the mutilating operation of exenteration are enumerated. They usually involve a malignant neoplasm of the orbital contents, primary, direct extension, or adnexal tissue that cannot be controlled by simple excision or irradiation. Surgically, subtotal exenteration with partial preservation of lids and even conjunctiva may be achieved occasionally. However, total exenteration may be lifesaving. Techniques and precautions are discussed. Advantages and disadvantages of skin grafting that influence the postoperative care are noted.

Walter Sydney Atkinson, MD

Images

Arterial embolization of orbital hemangiomas

A patient with multiple orbital hemangiomas benefitting from the adjunct treatment of transcatheter selective arterial embolization has been presented. The interdisciplinary team effort for this relatively new modality of treatment is called to the attention of the ophthalmologist for consideration in management with difficult or inoperable orbital vascular lesions or arteriovenous malformations with or without intracranial manifestations.

Alterations in rabbit alveolar macrophages as a result of traumatic shock

Biochemical and electron microscope studies were conducted to determine the effects of traumatic shock on rabbit alveolar macrophages. Both resting and phagocytosing macrophages from the shocked animals, in comparison to comparable control macrophages, showed increased release of acid phosphatase from the cells into medium upon incubation in vitro, but decreases in the total content of acid phosphatase and beta-glucuronidase. Studies by electron microscopy showed ultrastructural alterations in macrophages from shocked animals consisting of a reduction in the number or a complete absence of lysosomes and, in some cases, increased amounts of rough endoplasmic reticulum and free ribosomes. In vitro incubation of macrophages from shocked animals with Pseudomonas aeruginosa showed that the process of bacterial ingestion was not impaired nor were the numbers of bacteria ingested decreased as compared to control macrophages. However, the ability of macrophages from shocked animals to destroy ingested bacteria appeared to be significantly altered. Extensive degradation of Pseudomonas was observed within phagocytic vacuoles of control macrophages after 15 minutes of incubation. In contrast, the majority of ingested organisms in macrophages from shocked animals showed no evidence of degradative changes.

Bone changes in the adult anophthalmic orbit influencing oculoplastic reconstructive considerations

Decreased orbital development following enucleation is a well recognized condition in the young person and is lessened by orbital implantation at the time of inital surgery. Pfeiffer, some 30 years ago, suggested that bone changes as well as the soft tissue changes could also continue to take place in the adult resulting in added orbital changes. While this has been questioned, the findings originally reported by Pfeiffer are firmly substantiated by roentgenograms and documented in this report. If there has been a significant interval of time following the enucleation, careful roentgenographic evaluation prior to cosmetic oculoplastic revision of the orbit should be done even in the adult.

Further observations on atypical band keratopathy in glaucoma patients

Images

Growth retardation and volume determinations of the anophthalmic orbit

Images

Atypical band keratopathy in glaucoma patients

Images

Marsupialization of inoperable orbital dermoids

Images