Sumona Mondal

Predicting Home and Community Walking Activity in People With Stroke

OBJECTIVE To determine the ability of the 6-minute walk test (6MWT) and other commonly used clinical outcome measures to predict home and community walking activity in high-functioning people with stroke. DESIGN Cross-sectional. SETTING Outpatient physical therapy clinic. PARTICIPANTS Participants (N=32) with chronic stroke (n=19; >6mo poststroke) with self-selected gait speed (GS) faster than .40m/s and age-matched healthy participants (n=13). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES INDEPENDENT VARIABLES 6MWT, self-selected GS, Berg Balance Scale (BBS), lower extremity motor section of the Fugl-Meyer Assessment, and Stroke Impact Scale. Dependent variable: average steps taken per day during a 7-day period, measured using an accelerometer. RESULTS 6MWT, self-selected GS, and BBS were moderately related to home and community walking activity. The 6MWT was the only predictor of average steps taken per day; it explained 46% of the variance in steps per day. CONCLUSIONS The 6MWT is a useful outcome measure in higher functioning people with stroke to guide intervention and assess community walking activity.

Decay of bacterial pathogens, fecal indicators, and real-time quantitative PCR genetic markers in manure amended soils

ABSTRACT This study examined persistence and decay of bacterial pathogens, fecal indicator bacteria (FIB), and emerging real-time quantitative PCR (qPCR) genetic markers for rapid detection of fecal pollution in manure-amended agricultural soils. Known concentrations of transformed green fluorescent protein-expressing Escherichia coli O157:H7/pZs and red fluorescent protein-expressing Salmonella enterica serovar Typhimurium/pDs were added to laboratory-scale manure-amended soil microcosms with moisture contents of 60% or 80% field capacity and incubated at temperatures of −20°C, 10°C, or 25°C for 120 days. A two-stage first-order decay model was used to determine stage 1 and stage 2 first-order decay rate coefficients and transition times for each organism and qPCR genetic marker in each treatment. Genetic markers for FIB (Enterococcus spp., E. coli, and Bacteroidales) exhibited decay rate coefficients similar to that of E. coli O157:H7/pZs but not of S. enterica serovar Typhimurium/pDs and persisted at detectable levels longer than both pathogens. Concentrations of these two bacterial pathogens, their counterpart qPCR genetic markers (stx1 and ttrRSBCA, respectively), and FIB genetic markers were also correlated (r = 0.528 to 0.745). This suggests that these qPCR genetic markers may be reliable conservative surrogates for monitoring fecal pollution from manure-amended land. Host-associated qPCR genetic markers for microbial source tracking decayed rapidly to nondetectable concentrations, long before FIB, Salmonella enterica serovar Typhimurium/pDs, and E. coli O157:H7/pZs. Although good indicators of point source or recent nonpoint source fecal contamination events, these host-associated qPCR genetic markers may not be reliable indicators of nonpoint source fecal contamination events that occur weeks following manure application on land.

Human papillomavirus type 16 E6 and E 7 proteins alter NF-kB in cultured cervical epithelial cells and inhibition of NF-kB promotes cell growth and immortalization

The NF-kB family of transcription factors regulates important biological functions including cell growth, survival and the immune response. We found that Human Papillomavirus type 16 (HPV-16) E7 and E6/E7 proteins inhibited basal and TNF-alpha-inducible NF-kB activity in human epithelial cells cultured from the cervical transformation zone, the anatomic region where most cervical cancers develop. In contrast, HPV-16 E6 regulated NF-kB in a cell type- and cell growth-dependent manner. NF-kB influenced immortalization of cervical cells by HPV16. Inhibition of NF-kB by an IkB alpha repressor mutant increased colony formation and immortalization by HPV-16. In contrast, activation of NF-kB by constitutive expression of p65 inhibited proliferation and immortalization. Our results suggest that inhibition of NF-kB by HPV-16 E6/E7 contributes to immortalization of cells from the cervical transformation zone.

Variation in concentrations of three mercury (Hg) forms at a rural and a suburban site in New York State

Tekran® Hg speciation systems were used at a rural site (Huntington Forest, NY; HF) and a suburban site (Rochester, NY; ROC) to measure gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM), and fine particulate-bound mercury (PBM2.5) concentrations for two years (December 2007 to November 2009). Ancillary data were also available from the New York State Department of Environmental Conservation and the United States Environmental Protection Agency Clean Air Status and Trends Network. Seasonal GEM concentrations were similar at both sites and influenced by factors such as the planet boundary layer (PBL) height and mercury emissions from snow, soil, and point sources. In some seasons, O3 was negatively correlated with GEM at ROC and positively correlated with GEM at HF. At HF, O3 was correlated with GOM and was typically higher in the afternoon. The cause of this pattern may be photochemical reactions during the day, and the GOM diel pattern may also be due to deposition which is enhanced by dew formation during the night and early morning. PBM2.5 concentrations were higher in winter at both sites. This is indicative of local wood combustion for space heating in winter, increased sorption to particles at lower temperatures, and lower PBL in the winter. At the suburban site, 2 of 12 events with enhanced GEM/CO ratios were poorly correlated with SO2/GOM, implying that these two events were due either to long range transport or regional metallurgical industries in Canada.

Improved Tolerance Factors for Multivariate Normal Distributions

ABSTRACT In this article, an improved method of computing tolerance factors for multivariate normal distributions is proposed. The method involves an approximation and simulation, and is more accurate than the several approximate methods considered in Krishnamoorthy and Mathew (1999). The accuracies of the tolerance regions are evaluated using Monte Carlo simulation. Simulation study shows that the new approach is very satisfactory even for small samples. Tolerance factors based on the proposed approach are tabulated for the dimension of the normal distribution p = 2(1)10, and various sample sizes ranging from 2p + 1 to 1000.

The effects of diabetes and/or peripheral neuropathy in detecting short postural perturbations in mature adults.

BackgroundThis study explored the effects of diabetes mellitus (DM) and peripheral neuropathy (PN) on the ability to detect near-threshold postural perturbations.Methods83 subjects participated; 32 with type II DM (25 with PN and 7 without PN), 19 with PN without DM, and 32 without DM or PN. Peak acceleration thresholds for detecting anterior platform translations of 1 mm, 4 mm, and 16 mm displacements were determined. A 2(DM) × 2(PN) factorial MANCOVA with weight as a covariate was calculated to compare acceleration detection thresholds among subjects who had DM or did not and who had PN or did not.ResultsThere was a main effect for DM but not for PN. Post hoc analysis revealed that subjects with DM required higher accelerations to detect a 1 mm and 4 mm displacement.ConclusionOur findings suggest that PN may not be the only cause of impaired balance in people with DM. Clinicians should be aware that diabetes itself might negatively impact the postural control system.

Inhibition of the epidermal growth factor receptor by erlotinib prevents immortalization of human cervical cells by Human Papillomavirus type 16

The Human Papillomavirus type-16 (HPV-16) E6 and E7 oncogenes are selectively retained and expressed in cervical carcinomas, and expression of E6 and E7 is sufficient to immortalize human cervical epithelial cells. Expression of the epidermal growth factor receptor (EGFR) is often increased in cervical dysplasia and carcinoma, and HPV oncoproteins stimulate cell growth via the EGFR pathway. We found that erlotinib, a specific inhibitor of EGFR tyrosine kinase activity, prevented immortalization of cultured human cervical epithelial cells by the complete HPV-16 genome or the E6/E7 oncogenes. Erlotinib stimulated apoptosis in cells that expressed HPV-16 E6/E7 proteins and induced senescence in a subpopulation of cells that did not undergo apoptosis. Since immortalization by HPV E6/E7 is an important early event in cervical carcinogenesis, the EGFR is a potential target for chemoprevention or therapy in women who have a high risk for cervical cancer.

Comparative study of methanogens in one- and two-stage anaerobic digester treating food waste

Changes in methanogenic archaea were investigated in pilot-scale experiments during one- and two-stage mesophilic anaerobic digestion (AD) of food waste. Methane yields were 379.7±75.3 liters of methane per kg of volatile solids [L-CH 4 (kg-VS) −1 ] added to the system, during one-stage operation, and 446±922 L-CH 4 (kg-VS) −1 added during two-stage operation. Populations of methanogenic archaea were monitored quantitatively by targeting the functional gene for methyl-coenzyme-M reductase ( mcrA ) using real-time quantitative polymerase chain reaction techniques. During one-stage operation, mean mcrA gene concentrations were 2.48×10 9 ±2.7×10 9 copies ml −1 . Two-stage operation yielded mean mcrA gene concentrations of 9.85×10 8 ±8.2×10 8 copies ml −1 in the fermentation and 1.76×10 10 ±8.5×10 9 copies ml −1 in the methanogenesis reactors, respectively. Diversity of archaea in the methanogenic reactors was investigated by denaturing gradient gel electrophoresis targeting the V3 region of 16S rRNA of archaea. The Shannon index ( H ) was 2.98 for one-stage operation and 7.29 for two-stage operation, suggesting greater archaeal diversity in the two-stage AD. The fivefold increase in methanogenic archaea populations during the two-stage operation, as indicated by mcrA gene concentration, corresponded to an increase in methane production rates. While the diversity may also be related to the stability of the microbial bioprocesses and improved methane production rates, the correlation between diversity and production rates should be studied further.

Gaseous Elemental Mercury (GEM) Emissions from Snow Surfaces in Northern New York

Snow surface-to-air exchange of gaseous elemental mercury (GEM) was measured using a modified Teflon fluorinated ethylene propylene (FEP) dynamic flux chamber (DFC) in a remote, open site in Potsdam, New York. Sampling was conducted during the winter months of 2011. The inlet and outlet of the DFC were coupled with a Tekran Model 2537A mercury (Hg) vapor analyzer using a Tekran Model 1110 two port synchronized sampler. The surface GEM flux ranged from −4.47 ng m−2 hr−1 to 9.89 ng m−2 hr−1. For most sample periods, daytime GEM flux was strongly correlated with solar radiation. The average nighttime GEM flux was slightly negative and was not well correlated with any of the measured meteorological variables. Preliminary, empirical models were developed to estimate GEM emissions from snow surfaces in northern New York. These models suggest that most, if not all, of the Hg deposited with and to snow is reemitted to the atmosphere.

Tolerance Factors in Multiple and Multivariate Linear Regressions

In this article, an improved method of computing tolerance factors for constructing tolerance regions in a multivariate linear regression model is proposed. The method is based on a chi-square approximation to the distribution of a linear function of noncentral chi-square variables and simulation. The merits of the proposed approach and the usual simulation method considered in Lee and Mathew (2004) are evaluated using Monte Carlo simulation. The study indicates that the proposed approach is stable and accurate even for small samples, and better than available methods. For constructing two-sided tolerance intervals in multiple linear regression, coverage level adjusted one-sided tolerance factors are shown to be better than available approximate tolerance factors. The results based on the coverage level adjusted one-sided tolerance factors are as good as the ones based on the exact two-sided tolerance factors in many cases.