Spatially-explicit estimation of Wright's neighborhood size in continuous populations

Effective population size (Ne) is an important parameter in conservation genetics because it quantifies a population’s capacity to resist loss of genetic diversity due to inbreeding and drift. The classical approach to estimate Ne from genetic data involves grouping sampled individuals into discretely defined subpopulations assumed to be panmictic. Importantly, this assumption does not capture the continuous nature of populations genetically isolated by distance. Alternative approaches based on Wright’s genetic neighborhood concept quantify the local number of breeding individuals (NS) in a continuous population (as opposed to the global Ne). However, they do not reflect the potential for NS to vary spatially nor do they account for the resistance of a heterogeneous landscape to gene flow (isolation by resistance). Here, we describe an application of Wright’s neighborhood concept that provides spatially-explicit estimates of local NS from genetic data in continuous populations isolated by distance or resistance. We delineated local neighborhoods surrounding each sampled individual based on sigma (), a measure of the local extent of breeding. When was known, the linkage disequilibrium method applied to local neighborhoods produced unbiased estimates of NS that were highly variable across the landscape. NS near the periphery or areas surrounded by high resistance was as much as an order of magnitude lower compared to the center, raising the potential for a spatial component to extinction vortex dynamics in continuous populations. When is not known, it may be estimated from genetic data, but two methods we evaluated identified analysis extents that produced considerable bias or error in the estimate of NS. When is known or accurately estimated, and the assumptions of Wright’s neighborhood are met, the method we describe provides spatially explicit information regarding short-term genetic processes that may inform conservation genetic analyses and management

The Covid-19 Crisis in the Cali-Baja Region

The central research question posed was “what have been the economic, public health, and social impacts of the Covid-19 crisis in the Cali- Baja region?” The Covid-19 pandemic has impacted several communities around the world, and economic and health consequences have also exacerbated existing issues. In Cali Baja, the nature of having a population dependent upon cross-border travel and collaboration has resulted in unique ramifications for businesses, governments, and individuals. Understanding the ways in which this pandemic has, and continues to, spread as well as how it disproportionately affects specific populations provides needed insight for governmental responses for the inevitability of another pandemic or crisis. Despite the closure of nonessential travel, the patterns of epidemiology continued roughly parallel on both sides of the border. About 100,000 essential travelers crossed daily from Mexico to supply labor to American companies, supporting the U.S. economy and its production. Deep socio-cultural connections have also been nurtured as families establish links within both nations. What can be drawn from this report is the identification of the interconnectedness of the Cali Baja community, and the need for binational governance to take place when crises such as this occur. In interviews with local stakeholders many recommendations were presented. These include the need for: Adopting a binational perspective in government responses Promoting cross border collaborations Advancing border processes and technology Redefining the border narrative more generall

US-Mexico Relations in an Age of Uncertainty

This essay reviews the following works: A Tale of Two Eagles: The US-Mexico Bilateral Defense Relationship Post Cold War. By Craig A. Deare. Lanham, MD: Rowman and Littlefield, 2017. Pp. vii + 436. $45.00 paperback. ISBN: 9781442269446. The U.S.-Mexican Border Today: Conflict and Cooperation in Historical Perspective. By Paul Ganster with David E. Lorey. 3rd ed. Lanham, MD: Rowman and Littlefield, 2017. Pp. vii + 296.$29.00 paperback. ISBN: 9781442231115. American Crossings: Border Politics in the Western Hemisphere. Edited by Maiah Jaskoski, Arturo C. Sotomayor, and Harold A. Trinkunas. Baltimore: Johns Hopkins University Press, 2015. Pp. vii + 238. $39.95 paperback. ISBN:9781421418308. Two Nations Indivisible: Mexico, the United States, and the Road Ahead. By Shannon K. O’Neil. New York: Oxford University Press, 2013. Pp. vii + 239.$27.95 hardcover. ISBN: 9780199898336. Binational Human Rights: The U.S.-Mexico Experience. Edited by William Paul Simmons and Carol Mueller. Philadelphia: University of Pennsylvania Press, 2014. Pp. 312. $27.95 hardcover. ISBN: 9780812246285. Mexico and United States: The Politics of Partnership. Edited by Peter H. Smith and Andrew Selee. Boulder, CO: Lynne Rienner Publishers, 2013. Pp. vii + 243.$23.00 paperback. ISBN: 9781588268938

A study to compare two methods of near astigmatism testing

A study to compare two methods of near astigmatism testin

Habitat Use and Population Densities of Rain Forest Chameleons in the East Usambara Mountains of Tanzania [poster]

Conclusions: Chamaeleo dilepis and Ri. brevicaudatus are absent from forest at this elevation (852-1103m), while K. matschiei, K. vosseleri, K. tenuis, and R. spinosus are relatively scarce in the forest. Trioceros deremensis and R. temporalis are common, but density varies greatly. The endemic and scarce K. matschiei and K. vosseleri may be of concern given their scarcity in forest habitat. Density estimates in other habitat types are needed to determine status. For accurate density estimates, it is important to consider seasonal variation in density and animals too high to be observed in surveys

Re-evaluating causal modeling with mantel tests in landscape genetics

The predominant analytical approach to associate landscape patterns with gene flow processes is based on the association of cost distances with genetic distances between individuals. Mantel and partial Mantel tests have been the dominant statistical tools used to correlate cost distances and genetic distances in landscape genetics. However, the inherent high correlation among alternative resistance models results in a high risk of spurious correlations using simple Mantel tests. Several refinements, including causal modeling, have been developed to reduce the risk of affirming spurious correlations and to assist model selection. However, the evaluation of these approaches has been incomplete in several respects. To demonstrate the general reliability of the causal modeling approach with Mantel tests, it must be shown to be able to correctly identify a wide range of landscape resistance models as the correct drivers relative to alternative hypotheses. The objectives of this study were to (1) evaluate the effectiveness of the originally published causal modeling framework to support the correct model and reject alternative hypotheses of isolation by distance and isolation by barriers and to (2) evaluate the effectiveness of causal modeling involving direct competition of all hypotheses to support the correct model and reject all alternative landscape resistance models. We found that partial Mantel tests have very low Type II error rates, but elevated Type I error rates. This leads to frequent identification of support for spurious correlations between alternative resistance hypotheses and genetic distance, independent of the true resistance model. The frequency in which this occurs is directly related to the degree of correlation between true and alternative resistance models. We propose an improvement based on the relative support of the causal modeling diagnostic tests

A Low Cost, Portable Fluorescence Correlation Spectrometer for Disease Diagnosis

People being treated for HIV need to periodically test to determine if their antiviral medication is effectively keeping their viral loads at a safe level. Individuals living in rural areas of developing countries would be more likely to get these viral load tests if an instrument existed which reduced costs and was small and rugged enough to be brought to the client rather than require the client to travel for hours to a clinic. The Diagnostics for Viral Disease team is developing such a device in cooperation with Dr. Edgar Simulundu and the Macha Research Trust in Zambia. Our design is based on advanced fluorescence spectroscopy utilizing a fluorescence protein probe, confocal optics, and low-cost, low-power electronics. This poster reviews work done in three subsystems of the overall instrument. First, we have optimized the program used during burst analysis spectroscopy for identification of individual viruses in dilute samples. Second, we have confirmed the operation of the amplifying and discriminating sections of the photon processing circuitry which converts light pulses into a digital signal ready to be processed in the signal analysis subsystem. Finally, we have completed the Field Programmable Gate Array (FPGA) and Raspberry Pi programming allowing successful transfer of the results of the signal processing in the FPGA to the Raspberry Pi for display to the end user. Going forward we will integrate these subsystems into a fully functional exploded prototype ready for the final stage of condensing the design into a portable prototype that can be tested and delivered to our client. Funding for this work provided by The Collaboratory for Strategic Partnerships and Applied Research.https://mosaic.messiah.edu/engr2022/1003/thumbnail.jp

Pediatric Critical Care in Resource-Limited Settings-Overview and Lessons Learned.

Pediatric critical care is an important component of reducing morbidity and mortality globally. Currently, pediatric critical care in low middle-income countries (LMICs) remains in its infancy in most hospitals. The majority of hospitals lack designated intensive care units, healthcare staff trained to care for critically ill children, adequate numbers of staff, and rapid access to necessary medications, supplies and equipment. In addition, most LMICs lack pediatric critical care training programs for healthcare providers or certification procedures to accredit healthcare providers working in their pediatric intensive care units (PICU) and high dependency areas. PICU can improve the quality of pediatric care in general and, if properly organized, can effectively treat the severe complications of high burden diseases, such as diarrhea, severe malaria, and respiratory distress using low-cost interventions. Setting up a PICU in a LMIC setting requires planning, specific resources, and most importantly investment in the nursing and permanent medical staff. A thoughtful approach to developing pediatric critical care services in LMICs starts with fundamental building blocks: training healthcare professionals in skills and knowledge, selecting resource appropriate effective equipment, and having supportive leadership to provide an enabling environment for appropriate care. If these fundamentals can be built on in a sustainable manner, an appropriate critical care service will be established with the potential to significantly decrease pediatric morbidity and mortality in the context of public health goals as we reach toward the sustainable development goals

Spatio-temporal dynamics of Marbled Murrelet hotspots during nesting in nearshore waters along the Washington to California coast

The Marbled Murrelet, Brachyramphus marmoratus, is a federally listed alcid that forages in nearshore waters of the Pacific Northwest, and nests in adjacent older-forest conifers within 40-80 km of shore. To estimate abundance and distribution of murrelets, we conduct at-sea surveys from May to July each year, starting in 2000 and continuing to present. We record numbers of individuals sighted by using distance-based transects and compute annual estimates of density after adjusting for detectability. At-sea transects are subdivided into 5-km segments, and we summarized mean and variance of density at each segment in Puget Sound and along the coast from the Canadian border South to San Francisco Bay. We used a boosted regression tree analysis to investigate the contributions of marine and terrestrial attributes on murrelet abundance in each segment. We observed that terrestrial attributes, especially the amount and pattern of suitable nesting habitat in proximity to each segment, made the strongest contribution, but that marine attributes also helped explain variation in murrelet abundance. Hotspots of murrelet abundance therefore reflect not only suitable marine foraging habitat but proximity of suitable inland nesting habitat

Advanced altimetry

The radar altimeter being developed for the Ocean Topography Experiment (TOPEX) will have an inherent instrument precision of 2 to 3 cm. While some minor refinements may be possible in the future, major geophysical advances could be made if altimetric measurements over a wide swath of the Earth's surface were possible. The NASA Headquarters Oceanic Processes Branch is supporting a 3-year investigation of the technological issues inherent in the precision measurement of topography from spaceborne platforms at angles off-nadir. To explore the off-nadir measurement of topography, a flexible, airborne radar instrument system is being developed. Its hardware design is now complete, and it is made up of several subsystems. The antenna selected is a dielectric lens of .894 m diameter. The RF subsystem uses phase-locked oscillators, FET solid-state amplifiers, and times four frequency multipliers to develop a transmit signal at a frequency of 36.0 GHz and a local oscillator signal at a frequency of 35.4 GHz. Lecroy 6880 digitizers under computer control digitize the five receiver outputs. The digital subsystem consists of six single-board Heurikon processors. At this time, the instrument construction continues with final system integration planned for November 1988