Loneliness among homeless-experienced older adults with cognitive or functional impairments: qualitative findings from the HOPE HOME study.

BACKGROUND: Loneliness is more common in older adults and those who face structural vulnerabilities, including homelessness. The homeless population is aging in the United States; now, 48% of single homeless adults are 50 and older. We know little about loneliness among older adults who have experienced homelessness. We aimed to describe the loneliness experience among homeless-experienced older adults with cognitive and functional impairments and the individual, social, and structural conditions that shaped these loneliness experiences. METHODS: We purposively sampled 22 older adults from the HOPE HOME study, a longitudinal cohort study among adults aged 50 years or older experiencing homelessness in Oakland, California. We conducted in-depth interviews about participants perceived social support and social isolation. We conducted qualitative content analysis. RESULTS: Twenty participants discussed loneliness experience, who had a median age of 57 and were mostly Black (80%) and men (65%). We developed a typology of participants' loneliness experience and explored the individual, social, and structural conditions under which each loneliness experience occurred. We categorized the loneliness experience into four groups: (1) "lonely- distressed", characterized by physical impairment and severe isolation; (2) "lonely- rather be isolated", reflecting deliberate social isolation as a result of trauma, marginalization and aging-related resignation; (3) "lonely- transient", as a result of aging, acceptance and grieving; and (4) "not lonely"- characterized by stability and connection despite having experienced homelessness. CONCLUSIONS: Loneliness is a complex and heterogenous social phenomenon, with homeless-experienced older adults with cognitive or functional impairments exhibiting diverse loneliness experiences based on their individual life circumstances and needs. While the most distressing loneliness experience occurred among those with physical impairment and mobility challenges, social and structural factors such as interpersonal and structural violence during homelessness shaped these experiences.

Efficacy and Accuracy of Diagnosing Septic Arthritis: How Effective are Current Methods for Timely Diagnosis of Septic Arthritis?

The diagnosis of septic arthritis requires a reliance on ancillary tests, including synovial fluid white blood cell count (jWBC), percentage of polymorphonuclear leukocytes (%PMN), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). This study evaluated these tests to determine their diagnostic utility in suspected septic arthritis. A retrospective chart review was performed on patients admitted to an urban hospital who underwent arthrocentesis. The authors evaluated the jWBC, %PMN, ESR, and CRP with receiver operating characteristic (ROC) curve analyses. Two hundred sixty-five patients met inclusion criteria. Sixty-three had a culture-positive aspirate. ROC curve analysis resulted in an area under the curve (AUC) of 0.80 for jWBC with cutoff point of 22,563 cells/mm3 and an AUC of 0.71 for %PMN with cutoff point of 90.5%. CRP and ESR had AUC values of 0.62 and 0.61, respectively. The culture-positive cohort had higher elevations in all assessed diagnostic tests. However, AUC data for ESR and CRP showed little diagnostic utility. Additionally, sensitivities and specificities of jWBC and %PMN were too low. Associated cutoff points would result in excessive unnecessary operative intervention. Further studies should incorporate synovial fluid biomarkers into the workup of a suspected septic joint. (Journal of Surgical Orthopaedic Advances 33(2):108-111, 2024).

Short solvent model for ion correlations and hydrophobic association.

Coulomb interactions play a major role in determining the thermodynamics, structure, and dynamics of condensed-phase systems, but often present significant challenges. Computer simulations usually use periodic boundary conditions to minimize corrections from finite cell boundaries but the long range of the Coulomb interactions generates significant contributions from distant periodic images of the simulation cell, usually calculated by Ewald sum techniques. This can add significant overhead to computer simulations and hampers the development of intuitive local pictures and simple analytic theory. In this paper, we present a general framework based on local molecular field theory to accurately determine the contributions from long-ranged Coulomb interactions to the potential of mean force between ionic or apolar hydrophobic solutes in dilute aqueous solutions described by standard classical point charge water models. The simplest approximation leads to a short solvent (SS) model, with truncated solvent-solvent and solute-solvent Coulomb interactions and long-ranged but screened Coulomb interactions only between charged solutes. The SS model accurately describes the interplay between strong short-ranged solute core interactions, local hydrogen-bond configurations, and long-ranged dielectric screening of distant charges, competing effects that are difficult to capture in standard implicit solvent models.

Spatial analysis of individual- and village-level sociodemographic characteristics associated with age at marriage among married adolescents in rural Niger.

BACKGROUND: Niger has the highest prevalence of child marriage in the world. While child marriage in Niger is clearly normative in the sense that it is commonly practiced, the social and contextual factors that contribute to it are still unclear. METHODS: Here, we tested the importance of village-level factors as predictors of young age at marriage for a group of married adolescent girls (N = 1031) in the Dosso district of rural Niger, using multi-level and geographic analyses. We aggregated significant individual level factors to determine whether, independent of a girl's own sociodemographic characteristics, the impact of each factor is associated at the village level. Finally, we tested for spatial dependence and heterogeneity in examining whether the village-level associations we find with age at marriage differ geographically. RESULTS: The mean age of marriage for girls in our study was 14.20 years (SD 1.8). Our statistical results are consistent with other literature suggesting that education is associated with delayed marriage, even among adolescent girls. Younger ages at marriage are also associated with a greater age difference between spouses and with a greater likelihood of women being engaged in agricultural work. Consistent with results at the individual level, at the village level we found that the proportion of girls who do agricultural work and the mean age difference between spouses were both predictive of a lower age at marriage for individual girls. Finally, mapping age at marriage at the village level revealed that there is geographical variation in age at marriage, with a cluster of hot spots in the Hausa-dominated eastern area where age at marriage is particularly low and a cluster of cold spots in the Zarma-dominated western areas where age at marriage is relatively high. CONCLUSIONS: Our findings suggest that large-scale approaches to eliminating child marriage in these communities may be less successful if they do not take into consideration geographically and socially determined contextual factors at the village level.

In vitro and in vivo metabolic stability of various fragrance materials and insect repellent in rainbow trout (Oncorhynchus mykiss).

Commercial fragrances consist of several thousand natural and synthetic substances formulated in complex combinations. These ingredients are frequently blended at very low concentrations but they are typically lipophilic and a few of them (e.g., synthetic musks) have been detected in aquatic systems, albeit at low concentrations. Few fragrances have guideline in vivo data on bioaccumulation, so in silico modeling has been widely used to estimate bioconcentration factors (BCFs). This study used in vitro metabolism assays with trout S9 cell fractions and cryopreserved hepatocytes to improve estimates of fish BCFs and to test published methods for extrapolating in vitro metabolic rate data to whole fish and corresponding BCFs. These estimates for several chemicals were compared with new in vivo bioconcentration measurements and previously published data on fragrances and the insect repellent, DEET. In total, 17 (20 including isomers) fragrance chemicals (abalyn, amberwood, amboryl acetate, bisabolene, cedroxide, coniferan, elemol, givescone, maritima, precyclemone B, polysantol, sandela, sanjinol, santalex, timberol and vernaldehyde) and DEET were metabolized at various rates. Only three materials tested did not appear to undergo enzymatic degradation (caryophyllene oxide, galaxolide and ketone patchouli). Even relatively slow rates of metabolism had a large influence on bioconcentration estimates. This work adds valuable information to the evolving body of work supporting the use of in vitro determinations of hepatic clearance to improve modeled predictions of bioaccumulation. It can also be used directly to help prioritize testing of potential bioaccumulative chemicals or serve as a more economical method for screening these chemicals.

In vitro evaluation of the metabolic stability of nine fragrance chemicals in trout and human hepatocytes.

In vitro metabolic stability of nine fragrance chemicals: p-tolyl acetate, cashmeran, ethylene brassylate, celestolide, galaxolide, traseolide, ambretone, tonalide and pentadecanolide, was evaluated in trout and human hepatocytes. The compounds were incubated with trout hepatocytes at 12°C and human hepatocytes at 37°C. Quantification of compound disappearance with time was performed using gas chromatography/mass spectrometry. in vivo hepatic intrinsic clearance values were calculated from the in vitro data. Significant metabolism was observed with trout hepatocytes for five of the nine fragrance chemicals, while all nine were metabolized significantly with human hepatocytes. Previously published models were used to examine expected bioaccumulation and persistence in whole organisms. Calculated half-lives due to metabolism of the nine chemicals are significantly shorter for humans than trout: <1 hour and <1 day, respectively. For all chemicals with demonstrated hepatic metabolism, the models indicate a lack of accumulation. For those where metabolism was demonstrated in trout, calculated bioconcentration factors would not be classified as bioaccumulative under prevailing regulatory systems.

Evaluation of the developmental toxicity of perfluorooctanesulfonate in the Anuran, Silurana tropicalis.

A 150-day post-metamorphosis (dpm) partial lifecycle study exposing Silurana tropicalis to <0.03 (control), 0.06, 0.13 0.25, 0.5 and 1.0 mg/L perfluorooctanesulfonate (PFOS) was conducted. A subset of specimens from the control and each treatment were evaluated at metamorphic completion. A significant increase in the median metamorphosis time was observed in the 1.0 mg/L PFOS treatment relative to the control. A modest increase in the occurrence, but not severity, of mild follicular hypertrophy was found in thyroid glands from organisms exposed to the 0.62 and 1.1 mg/L PFOS treatments. At 150 dpm, a concentration-dependent increase in whole body PFOS residues was measured ranging from 29.6 to 163.5 mg/kg in the 0.05 and 1.1 mg/L PFOS treatments. Decreased body weight and snout-vent length were noted in specimens exposed to 1.1 mg PFOS/L at the completion of metamorphosis. Body weight was reduced in the 1.1 mg/L PFOS concentration; however, snout-vent length was not affected by PFOS exposure at 150 dpm. An increased proportion of phenotypic males were noted in the 0.62 and 1.1 mg/L PFOS treatments. Abnormal ovary development characterized by size asymmetry, necrosis and formation of excessive fibrous connective tissue was identified in females exposed to 0.29 and 1.1 mg PFOS/L. Asymmetrically misshaped testes were found at 1.1 mg/L PFOS. Results suggested that PFOS is capable of interfering with S. tropicalis growth before metamorphic completion and growth and gonad development during juvenile development.

Effect of perfluorooctanesulfonate exposure on steroid hormone levels and steroidogenic enzyme activities in juvenile Silurana tropicalis.

The impact of the perfluoro-chemical, perfluorooctanesulfonate (PFOS), on gonadal steroidogenesis during sexual differentiation in Silurana tropicalis was examined because of its ubiquity in the environment, bioaccumulative nature and potential to disturb endocrine activity. A partial life cycle study exposing S. tropicalis to varying concentrations of PFOS 0.06, 0.13, 0.25, 0.50 and 1.0 mg PFOS/L [nominal]) was conducted. Gonad and plasma samples were collected from juvenile control specimens and organisms exposed to PFOS from early embryo through 150 days post-metamorphosis. Gonad CYP17, aromatase and 5α-reductase activities were measured. Plasma estradiol, testosterone, dihydrotestosterone (DHT) and gonadal testosterone were measured in both males and females. Increased plasma DHT and gonadal testosterone were found in PFOS-treated juvenile male S. tropicalis compared to controls. Decreased plasma estradiol, but not testosterone, was detected in PFOS-treated female S. tropicalis compared to controls. Plasma DHT was not detected and an increase in gonadal testosterone was detected in PFOS-treated female frogs. Female S. tropicalis exposed to PFOS exhibited a concentration-related decrease in the mean aromatase activity, but not 5α-reductase. PFOS exposure in male frogs induced a concentration-related increase in 5α-reductase activity, but did not alter aromatase activity compared to control frogs. A concentration-related increase in CYP 17,20-lyase activity, but not 17-hydroxylase activity, was found in both female and male S. tropicalis exposed to PFOS.

Long-ranged contributions to solvation free energies from theory and short-ranged models.

Long-standing problems associated with long-ranged electrostatic interactions have plagued theory and simulation alike. Traditional lattice sum (Ewald-like) treatments of Coulomb interactions add significant overhead to computer simulations and can produce artifacts from spurious interactions between simulation cell images. These subtle issues become particularly apparent when estimating thermodynamic quantities, such as free energies of solvation in charged and polar systems, to which long-ranged Coulomb interactions typically make a large contribution. In this paper, we develop a framework for determining very accurate solvation free energies of systems with long-ranged interactions from models that interact with purely short-ranged potentials. Our approach is generally applicable and can be combined with existing computational and theoretical techniques for estimating solvation thermodynamics. We demonstrate the utility of our approach by examining the hydration thermodynamics of hydrophobic and ionic solutes and the solvation of a large, highly charged colloid that exhibits overcharging, a complex nonlinear electrostatic phenomenon whereby counterions from the solvent effectively overscreen and locally invert the integrated charge of the solvated object.

A Randomized Controlled Trial to Reduce HIV-Related Risk in African American Men Who Have Sex with Men and Women: the Bruthas Project.

African American men who have sex with men and women (MSMW) are among the populations with the highest need for HIV prevention programs in the USA. We tested a theory-based, community participatory behavioral intervention aiming to reduce sexual risk for HIV transmission in this population. A randomized clinical trial involving 396 African American MSMW who were assigned to a 4-session intervention involving HIV testing and counseling (n = 199) or to a HIV testing and counseling only (n = 197) control. In the 4-session intervention program, counselors provided education on HIV and STI risk, condom use, HIV testing, interpersonal sexual dynamics with both male and female partners, and motivational "triggers" of condomless sex. Participants completed baseline, 6-month, and 9-month assessments, and changes in HIV behavioral risk indicators were examined by condition and time. There were no statistically significant differences in sexual risk between the intervention condition and the control condition. Regardless of condition, participants reported significant reductions in mean number of condomless sex events with female casual partners from baseline (6.04) to 6 months (2.58) and 9 months (1.47), and with male casual partners from baseline (2.61) to 6 months (1.18) and 9 months (0.60). Condition-by-time interaction effects and condition main effects were non-significant. Although there were no significant differences by condition, findings support the effects of brief behavioral counseling and HIV testing on reducing condomless sex with casual female and male partners among African American MSMW. Future research should examine further the potential for brief behavioral counseling to promote biomedical HIV prevention and to reduce co-morbid health issues such as substance use among African American MSMW.

Monitoring forest cover change within different reserve types in southern Ghana.

Rapid population and economic growth quickly degrade and deplete forest resources in many developing countries, even within protected areas. Monitoring forest cover change is critical for assessing ecosystem changes and targeting conservation efforts. Yet the most biodiverse forests on the planet are also the most difficult to monitor remotely due to their frequent cloud cover. To begin to reconcile this problem, we develop and implement an effective and efficient approach to mapping forest loss in the extremely cloud-prevalent southern Ghana region using dense time series Landsat 7 and 8 images from 1999 to 2018, based on median value temporal compositing of a novel vegetation index called the spectral variability vegetation index (SVVI). Resultant land-cover and land-use maps yielded 90 to 94% mapping accuracies. Our results indicate 625 km2 of forest loss within the 9800-km2 total mapping area, including within forest reserves and their environs between circa 2003 and 2018. Within the reserves, reduced forest cover is found near the reserve boundaries compared with their interiors, suggesting a more degraded environment near the edge of the protected areas. A fully protected reserve, Kakum National Park, showed little forest cover change compared with many other less protected reserves (such as a production reserve-Subri River). Anthropogenic activities, such as mining, agriculture, and built area expansion, were the main land-use transitions from forest. The reserves and census districts that are located near large-scale open pit mining indicated the most drastic forest loss. No significant correlation was found between the magnitudes of forest cover change and population density change for reserves and within a 1.5-km buffer surrounding the reserves. While other anthropogenic factors should be explored in relation to deforestation, our qualitative analysis revealed that reserve protection status (management policies) appears to be an important factor. The mapping approach described in this study provided a highly accurate and effective means to monitor land-use changes in forested and cloud-prone regions with great promise for application to improved monitoring of moist tropical and other forests characterized by high cloud cover.

Inhibition of germinal vesicle breakdown in Xenopus oocytes in vitro by a series of substituted glycol ethers.

A 24 hour in vitro Xenopus oocyte maturation (germinal vesicle breakdown [GVBD]) assay developed by Pickford and Morris (Environmental Health Perspectives, 1999, 107, 285-292) was used to screen a series of substituted glycol ethers (GEs). Substituted GEs included: ethylene glycol monomethyl ether (EGME); EG monoethyl ether (EGEE); EG monopropyl ether (EGPE); EG monobutyl ether (EGBE); EG monohexyl ether (EGHE); diethylene glycol monomethyl ether (DGME); triethylene glycol monomethyl ether (TGME); ethylene glycol monophenyl ether (EGPhE); EG monobenzyl ether (EGBeE); EG diphenyl ether (EGDPhE); and propylene glycol monophenyl ether (PGPhE). The GEs inhibited progesterone- or androstenedione-induced GVBD with the following relative potency: EGPhE > PGPhE > EGME >> EGEE ≥ EGBeE > EGPE >> EGBE >EGHE > EGDPhE >> DGME ≥ TGME, or EGPhE >> PGPhE >> EGBeE > EGDPhE > EGEE > EGME > EGPE > EGBE, EGHE, DGME and TGME, respectively. Further, [3 H]progesterone or [3 H]androstenedione binding affinities to the oocyte plasma membrane progesterone receptor (OMPR) or classical androgen receptor (AR) were: EGME > EGPhE ≥ PGPhE ≥ EGEE > EGBeE >> EGPE >> EGBE ≥ EGHE > EGDPhE, TGME, and DGME, or EGPhE > PGPhE >> EGBeE > EGDPhE >> EGEE ≥ EGME >> EGPE, EGBE, and EGHE > DGME and TGME, respectively. Binary joint mixture studies with the GVBD model using flutamide (AR antagonist) and EGPhE indicated that flutamide/EGPhE mixture acted in a concentration additive manner. The effects of substituted GE series, however, may be mediated through the OMPR; the potency of EGPhE may be the result of bimodal inhibition of both the OMPR and AR pathways.

Nitriles at Silica Interfaces Resemble Supported Lipid Bilayers.

Nitriles are important solvents not just for bulk reactions but also for interfacial processes such as separations, heterogeneous catalysis, and electrochemistry. Although nitriles have a polar end and a lipophilic end, the cyano group is not hydrophilic enough for these substances to be thought of as prototypical amphiphiles. This picture is now changing, as research is revealing that at a silica surface nitriles can organize into structures that, in many ways, resemble lipid bilayers. This unexpected organization may be a key component of unique interfacial behavior of nitriles that make them the solvents of choice for so many applications. The first hints of this lipid-bilayer-like (LBL) organization of nitriles at silica interfaces came from optical Kerr effect (OKE) experiments on liquid acetonitrile confined in the pores of sol-gel glasses. The orientational dynamics revealed by OKE spectroscopy suggested that the confined liquid is composed of a relatively immobile sublayer of molecules that accept hydrogen bonds from the surface silanol groups and an interdigitated, antiparallel layer that is capable of exchanging into the centers of the pores. This picture of acetonitrile has been borne out by molecular dynamics simulations and vibrational sum-frequency generation (VSFG) experiments. Remarkably, these simulations further indicate that the LBL organization is repeated with increasing disorder at least 20 Å into the liquid from a flat silica surface. Simulations and VSFG and OKE experiments indicate that extending the alkyl chain to an ethyl group leads to the formation of even more tightly packed LBL organization featuring entangled alkyl tails. When the alkyl portion of the molecule is a bulky t-butyl group, packing constraints prevent well-ordered LBL organization of the liquid. In each case, the surface-induced organization of the liquid is reflected in its interfacial dynamics. Acetonitrile/water mixtures are favored solvent systems for separations technologies such as hydrophilic interaction chromatography. Simulations had suggested that although a monolayer of water partitions to the silica surface in such mixtures, acetonitrile tends to associate with this monolayer. VSFG experiments reveal that, even at high water mole fractions, patches of well-ordered acetonitrile bilayers remain at the silica surface. Due to its ability to donate and accept hydrogen bonds, methanol also partitions to a silica surface in acetonitrile/methanol mixtures and can serve to take the place of acetonitrile in the sublayer closest to the surface. These studies reveal that liquid nitriles can exhibit an unexpected wealth of new organizational and dynamic behaviors at silica surfaces, and presumably at the surfaces of other chemically important materials as well. This behavior cannot be predicted from the bulk organization of these liquids. Our new understanding of the interfacial behavior of these liquids will have important implications for optimizing a wide range of chemical processes in nitrile solvents.

Identifying social and economic barriers to regular care and treatment for Black men who have sex with men and women (BMSMW) and who are living with HIV: a qualitative study from the Bruthas cohort.

BACKGROUND: There is little research regarding the ability of Black men who have sex with men and women (BMSMW) to access and maintain HIV-related health care and treatment adherence. This population, who often insist on secrecy about their same-sex desire, may experience unique barriers to seeking regular care and treatment. METHODS: From March 2011-April 2014, we recruited 396 BMSMW in the San Francisco Bay Area to be enrolled in our randomized controlled trial. At baseline we administered a behavioral survey assessing: demographics, homelessness, employment, history of incarceration, HIV status and disclosure practices, care and treatment adherence. 64 men reported living with HIV at intake. To learn more about their experiences, we recruited N = 25 to participate in qualitative interviews, which were conducted April-December 2014. Topics included: current living situation, diagnosis story, disclosure practices, experiences of accessing and maintaining care and treatment, and HIV-related stigma. Recordings were transcribed and coded for major themes. RESULTS: Despite being located in an area where treatment is plentiful, men faced social and economic barriers to maintaining regular care and treatment adherence. Several findings emerged to shed light on this quandary: (1) Competing needs particularly around attaining stable housing, food security, and money created barriers to treatment and care; (2) Side effects of HIV medications discouraged men from adhering to treatment; (3) Provider and Institutional level characteristics influenced care engagement; (4) Disclosure and social support made a difference in care and treatment behaviors; and (5) Participants expressed a desire for group-based intervention activities to support treatment and care among HIV+ BMSMW. Inadequate engagement in the continuum of care for HIV was born out in the quantitative data where 28% of participants did not know their Viral Load. CONCLUSIONS: A holistic approach to HIV health for BMSMW would appear to translate to better outcomes for men living with HIV, where a goal of viral suppression must also include attending to their basic social and economic support needs.

Best Practices for Chiropractic Care for Older Adults: A Systematic Review and Consensus Update.

OBJECTIVE: The purpose of this study was to update evidence-based recommendations on the best practices for chiropractic care of older adults. METHODS: The project consisted of a systematic literature review and a consensus process. The following were searched from October 2009 through January 2016: MEDLINE, Index to Chiropractic Literature, CINAHL (Cumulative Index to Nursing and Allied Health Literature), AMED (Allied and Complementary Medicine Database), Alt HealthWatch, Cochrane Database of Systematic Reviews, and Cochrane Registry of Controlled Trials. Search terms were: (manipulation, spinal OR manipulation, chiropractic OR chiropract*) AND (geriatric OR "older adult*"). Two reviewers independently screened articles and abstracts using inclusion and exclusion criteria. The systematic review informed the project steering committee, which revised the previous recommendations. A multidisciplinary panel of experts representing expertise in practice, research, and teaching in a variety of health professions serving older adults rated the revised recommendations. The RAND Corporation/University of California, Los Angeles methodology for a modified Delphi consensus process was used. RESULTS: A total of 199 articles were found; after exclusion criteria were applied, 6 articles about effectiveness or efficacy and 6 on safety were added. The Delphi process was conducted from April to June 2016. Of the 37 Delphi panelists, 31 were DCs and 6 were other health care professionals. Three Delphi rounds were conducted to reach consensus on all 45 statements. As a result, statements regarding the safety of manipulation were strengthened and additional statements were added recommending that DCs advise patients on exercise and that manipulation and mobilization contribute to general positive outcomes beyond pain reduction only. CONCLUSIONS: This document provides a summary of evidence-informed best practices for doctors of chiropractic for the evaluation, management, and manual treatment of older adult patients.

A Pattern-Based Definition of Urban Context Using Remote Sensing and GIS.

In Sub-Saharan Africa rapid urban growth combined with rising poverty is creating diverse urban environments, the nature of which are not adequately captured by a simple urban-rural dichotomy. This paper proposes an alternative classification scheme for urban mapping based on a gradient approach for the southern portion of the West African country of Ghana. Landsat Enhanced Thematic Mapper Plus (ETM+) and European Remote Sensing Satellite-2 (ERS-2) synthetic aperture radar (SAR) imagery are used to generate a pattern based definition of the urban context. Spectral mixture analysis (SMA) is used to classify a Landsat scene into Built, Vegetation and Other land covers. Landscape metrics are estimated for Built and Vegetation land covers for a 450 meter uniform grid covering the study area. A measure of texture is extracted from the SAR imagery and classified as Built/Non-built. SMA based measures of Built and Vegetation fragmentation are combined with SAR texture based Built/Non-built maps through a decision tree classifier to generate a nine class urban context map capturing the transition from unsettled land at one end of the gradient to the compact urban core at the other end. Training and testing of the decision tree classifier was done using very high spatial resolution reference imagery from Google Earth. An overall classification agreement of 77% was determined for the nine-class urban context map, with user's accuracy (commission errors) being lower than producer's accuracy (omission errors). Nine urban contexts were classified and then compared with data from the 2000 Census of Ghana. Results suggest that the urban classes appropriately differentiate areas along the urban gradient.

"We Remember the Pain": A qualitative study of intergenerational trauma among older adults experiencing homelessness in the HOPE HOME study.

Rates of homelessness among adults aged 50 and over are rising. Common strategies for exiting homelessness rely on social and family support. However, intergenerational trauma may disrupt these social support networks and contribute to homelessness. Understanding the impact of intergenerational trauma on living with family or friends may give insight into addressing homelessness among older adults. We purposefully sampled 46 adults who reported living with family or friends from the HOPE HOME study cohort (350 community-recruited adults, ≥ 50 years and experiencing homelessness in Oakland, California) and 19 family/friends who had hosted the participants in their living spaces. We conducted independent, semi-structured interviews and used grounded theory methodologies to analyze data. We identified four major themes from the interviews: (1) Intergenerational trauma was common and made it difficult to stay with family or friends; (2) Participants and hosts sought to protect future generations from intergenerational trauma; (3) Relationships endured despite intergenerational trauma; and (4) social structures exacerbated the impact of intergenerational trauma and played a significant role in perpetuating homelessness. Trauma-informed policies that confront the structures that propagate or exacerbate intergenerational trauma may mitigate their impact and facilitate housing for older adults.

Theory of impurity induced step pinning and recovery in crystal growth from solutions.

We extend the terrace-step-kink model of crystal growth to impure solutions where the impurities act as barriers to step motion. The effects of supersaturation, step curvature, step repulsions, and impurities on step motion are treated in a unified free energy framework. The model reproduces several features seen in experiments on growth of potassium dihydrogen phosphate crystals, wherein a dead zone at low supersaturations and a recovery of crystal growth by motion of large coherent step bunches at larger supersaturations are observed. We identify a key feature of solution growth that leads to these effects.

Histogram Curve Matching Approaches for Object-based Image Classification of Land Cover and Land Use.

The classification of image-objects is usually done using parametric statistical measures of central tendency and/or dispersion (e.g., mean or standard deviation). The objectives of this study were to analyze digital number histograms of image objects and evaluate classifications measures exploiting characteristic signatures of such histograms. Two histograms matching classifiers were evaluated and compared to the standard nearest neighbor to mean classifier. An ADS40 airborne multispectral image of San Diego, California was used for assessing the utility of curve matching classifiers in a geographic object-based image analysis (GEOBIA) approach. The classifications were performed with data sets having 0.5 m, 2.5 m, and 5 m spatial resolutions. Results show that histograms are reliable features for characterizing classes. Also, both histogram matching classifiers consistently performed better than the one based on the standard nearest neighbor to mean rule. The highest classification accuracies were produced with images having 2.5 m spatial resolution.

Estimating spatial inequalities of urban child mortality.

BACKGROUND: Recent studies indicate that the traditional rural-urban dichotomy pointing to cities as places of better health in the developing world can be complicated by poverty differentials. Knowledge of spatial patterns is essential to understanding the processes that link individual demographic outcomes to characteristics of a place. A significant limitation, however, is the lack of spatial data and methods that offer flexibility in data inputs. OBJECTIVE: This paper tackles some of the issues in calculating intra-urban child mortality by combining multiple data sets in Accra, Ghana and applying a new method developed by Rajaratnam et al. (2010) that efficiently uses summary birth histories for creating local-level measures of under-five child mortality (5q0). Intra-urban 5q0 rates are then compared with characteristics of the environment that may be linked to child mortality. METHODS: Rates of child mortality are calculated for 16 urban zones within Accra for birth cohorts from 1987 to 2006. Estimates are compared to calculated 5q0 rates from full birth histories. 5q0 estimates are then related to zone measures of slum characteristics, housing quality, health facilities, and vegetation using a simple trendline R2 analysis. RESULTS: Results suggest the potential value of the Rajaratnam et al. method at the micro-spatial scale. Estimated rates indicate that there is variability in child mortality between zones, with a spread of up to 50 deaths per 1,000 births. Furthermore, there is evidence that child mortality is connected to environmental factors such as housing quality, slum-like conditions, and neighborhood levels of vegetation.