Analysis of Increased Lensing Strength of Substructure in Galaxy Clusters

In 2019, an inconsistency between our observations and our simulations was discovered. We were finding that there were more cases of strong lensing appearing around galaxy cluster substructure than was predicted in simulations. This project is born as an effort to provide reasoning for this unexplained discrepancy. We begin by looking for cases of gravitational lensing which include a galaxy cluster potential as well as a single galaxy potential which is contained within the cluster. By looking at the resultant Lens Equation and specifying the cases, we find an analytical expression for the behavior of resulting images. We next apply this expression to both observed and simulated data to look for the best set of parameters to minimize the amount of mass that the single galaxy needs to have the strongest lensing effect. Finally, we propose an explanation for why galaxy cluster substructure has more lensing strength in observations than in simulations. We believe that shallower cluster mass profiles result in stronger lensing potentials for many of the singular galaxies which make up the cluster.This research was supported by the Undergraduate Research Opportunities Program (UROP).Lasko, Kekoa; Williams, Liliya L.R.. (2021). Analysis of Increased Lensing Strength of Substructure in Galaxy Clusters. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/223233

Forest landscape restoration in the drylands of Latin America

Forest Landscape Restoration (FLR) involves the ecological restoration of degraded forest landscapes, with the aim of benefiting both biodiversity and human well-being. We first identify four fundamental principles of FLR, based on previous definitions. We then critically evaluate the application of these principles in practice, based on the experience gained during an international, collaborative research project conducted in six dry forest landscapes of Latin America. Research highlighted the potential for FLR; tree species of high socioeconomic value were identified in all study areas, and strong dependence of local communities on forest resources was widely encountered, particularly for fuelwood. We demonstrated that FLR can be achieved through both passive and active restoration approaches, and can be cost-effective if the increased provision of ecosystem services is taken into account. These results therefore highlight the potential for FLR, and the positive contribution that it could make to sustainable development. However, we also encountered a number of challenges to FLR implementation, including the difficulty of achieving strong engagement in FLR activities among local stakeholders, lack of capacity for community-led initiatives, and the lack of an appropriate institutional and regulatory environment to support restoration activities. Successful implementation of FLR will require new collaborative alliances among stakeholders, empowerment and capacity building of local communities to enable them to fully engage with restoration activities, and an enabling public policy context to enable local people to be active participants in the decision making process. © 2012 by the author(s). Published here under license by the Resilience Alliance

Measurement of Fluorescence Phenomena from Yttrium and Gadolinium Oxysulfide Phosphors using a 45-MeV Proton Beam

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

A hominin first rib discovered at the Sterkfontein Caves, South Africa.

First ribs - the first or most superior ribs in the thorax - are rare in the hominin fossil record, and when found, have the potential to provide information regarding the upper thorax shape of extinct hominins. Here, we describe a partial first rib from Member 4 of the Sterkfontein Caves, South Africa. The rib shaft is broken away, so only the head and neck are preserved. The rib is small, falling closest to small-bodied Australopithecus first ribs (AL 288-1 and MH1). Given that it was recovered near the StW 318 femur excavation, which also represents a small individual, we suggest that the two may be associated. Three-dimensional geometric morphometric analyses were used to quantify the rib fragment morphology and compare it to extant hominoid and other fossil hominin ribs. While only the proximal end is preserved, our analyses show that South African Australopithecus share derived features of the proximal first rib more closely resembling A. afarensis and later hominins than great apes.NCS2016

The Rise and Fall of HIV in High-Prevalence Countries: A Challenge for Mathematical Modeling

Several countries with generalized, high-prevalence HIV epidemics, mostly in sub-Saharan Africa, have experienced rapid declines in transmission. These HIV epidemics, often with rapid onsets, have generally been attributed to a combination of factors related to high-risk sexual behavior. The subsequent declines in these countries began prior to widespread therapy or implementation of any other major biomedical prevention. This change has been construed as evidence of behavior change, often on the basis of mathematical models, but direct evidence for behavior changes that would explain these declines is limited. Here, we look at the structure of current models and argue that the common "fixed risk per sexual contact" assumption favors the conclusion of substantial behavior changes. We argue that this assumption ignores reported non-linearities between exposure and risk. Taking this into account, we propose that some of the decline in HIV transmission may be part of the natural dynamics of the epidemic, and that several factors that have traditionally been ignored by modelers for lack of precise quantitative estimates may well hold the key to understanding epidemiologic trends

Supplemental Iodide for Preterm Infants and Developmental Outcomes at 2 Years:an RCT

Background The recommendation for enteral iodide intake for preterm infants is 30–40 μg/kg/day and 1μg/kg/day for parenteral intake. Preterm infants are vulnerable to iodide insufficiency and thyroid dysfunction. The hypothesis tested whether, compared to placebo, iodide supplementation of preterm infants improves neurodevelopment. Methods A randomized controlled trial of iodide supplementation versus placebo in infants <31 weeks’ gestation. Trial solutions (sodium iodide or sodium chloride; dose 30μg/kg/day) were given within 42 hours of birth to the equivalent of 34 weeks’ gestation. The only exclusion criterion was maternal iodide exposure during pregnancy or delivery. Whole blood levels of thyroxine, thyrotropin and thyroid binding globulin were measured on four specific postnatal days. The primary outcome was neurodevelopmental status at two years’ of age, measured using the Bayley-III scales. The primary analyses are by intention-to-treat and data are presented also for survivors. Results 1,273 infants (637 intervention, 636 placebo) were recruited from 21 UK neonatal units. 131 infants died, and neurodevelopmental assessments were undertaken in 498 iodide and 499 placebo supplemented infants. There were no significant differences between the intervention and placebo groups in the primary outcome: mean difference Cognitive score, -0.34, 95% confidence interval (CI) -2.57 to 1.89; Motor composite score, 0.21, 95% CI -2.23 to 2.65; Language composite score, -0.05, 95%CI -2.48 to 2.39. There was evidence of weak interaction between iodide supplementation and hypothyroxinemic status in the Language composite score and one subtest score. Conclusions Overall iodide supplementation provided no benefit to neurodevelopment measured at 2 years of age

Osteogenic tumour in Australopithecus sediba: Earliest hominin evidence for neoplastic disease

We describe the earliest evidence for neoplastic disease in the hominin lineage. This is reported from the type specimen of the extinct hominin Australopithecus sediba from Malapa, South Africa, dated to 1.98 million years ago. The affected individual was male and developmentally equivalent to a human child of 12 to 13 years of age. A penetrating lytic lesion affected the sixth thoracic vertebra. The lesion was macroscopically evaluated and internally imaged through phase-contrast X-ray synchrotron microtomography. A comprehensive differential diagnosis was undertaken based on gross- and micro-morphology of the lesion, leading to a probable diagnosis of osteoid osteoma. These neoplasms are solitary, benign, osteoid and bone-forming tumours, formed from well-vascularised connective tissue within which there is active production of osteoid and woven bone. Tumours of any kind are rare in archaeological populations, and are all but unknown in the hominin record, highlighting the importance of this discovery. The presence of this disease at Malapa predates the earliest evidence of malignant neoplasia in the hominin fossil record by perhaps 200 000 years.NCS201

The Association between Parity and Subsequent Cardiovascular Disease in Women: The Atherosclerosis Risk in Communities Study

Background: Previous studies are inconclusive on the relationship between parity and cardiovascular disease (CVD), with few evaluating multiple cardiovascular outcomes. It is also unclear if any relationship between parity and CVD is independent of breastfeeding. We examined the associations between parity and cardiovascular outcomes, including breastfeeding adjustment. Materials and Methods: Data were from 8,583 White and African American women, 45-64 years of age, in the Atherosclerosis Risk in Communities Study. Coronary heart disease (CHD), myocardial infarction (MI), heart failure, and strokes were ascertained from 1987 to 2016 by annual interviews and hospital surveillance. Parity and breastfeeding were self-reported. Cox proportional hazards regression estimated hazard ratios (HR) for the association between parity and cardiovascular outcomes, adjusting for baseline sociodemographic, clinical and lifestyle factors, and breastfeeding. Results: Women reported no pregnancies (6.0%), or having 0 (1.6%), 1-2 (36.2%), 3-4 (36.4%), or 5+ (19.7%) live births. During 30 years follow-up, there were 1,352 CHDs, 843 MIs, 750 strokes, and 1,618 heart failure events. Compared with women with 1-2 prior births, those with prior pregnancies and no live births had greater incident CHD (HR=1.64, 95% confidence interval 1.14-2.42) and heart failure risk (1.46, 1.04-2.05), after adjustment for baseline characteristics. Women with 5+ births had greater risk of CHD (1.29, 1.10-1.52) and hospitalized MI (1.38, 1.13-1.69), after adjustment for baseline characteristics and breastfeeding. Conclusions: In a diverse U.S. cohort, a history of 5+ live births is associated with CHD risk, specifically, MI, independent of breastfeeding. Having a prior pregnancy and no live birth is associated with greater CHD and heart failure risk

Effects of Nosema apis, N. ceranae, and coinfections on honey bee (Apis mellifera) learning and memory

Western honey bees (Apis mellifera) face an increasing number of challenges that in recent years have led to significant economic effects on apiculture, with attendant consequences for agriculture. Nosemosis is a fungal infection of honey bees caused by either Nosema apis or N. ceranae. The putative greater virulence of N. ceranae has spurred interest in understanding how it differs from N. apis. Little is known of effects of N. apis or N. ceranae on honey bee learning and memory. Following a Pavlovian model that relies on the proboscis extension reflex, we compared acquisition learning and long-term memory recall of uninfected (control) honey bees versus those inoculated with N. apis, N. ceranae, or both. We also tested whether spore intensity was associated with variation in learning and memory. Neither learning nor memory differed among treatments. There was no evidence of a relationship between spore intensity and learning, and only limited evidence of a negative effect on memory; this occurred only in the co-inoculation treatment. Our results suggest that if Nosema spp. are contributing to unusually high colony losses in recent years, the mechanism by which they may affect honey bees is probably not related to effects on learning or memory, at least as assessed by the proboscis extension reflex