Sleep quality and quantity and associated factors among high school students from south Texas

Background. Insufficient and poor quality sleep among adolescents affects not only the cognitive functioning, but overall health of the individual. Existing research suggests that adolescents from varying ethnic groups exhibit differing sleep patterns. However, little research focuses on sleep patterns and associated factors (i.e. tobacco use, mental health indicators) among Hispanic youth. ^ Methods. The study population (n=2,536) included students in grades 9-12 who attended one of the three public high schools along the Texas-Mexico border in 2003. This was a cross sectional study using secondary data collected via a web-based, confidential, self-administered survey. Separate logistic regression models were estimated to identify factors associated with reduced (<9 hours/night) and poor quality sleep on average during weeknights. ^ Results. Of participants, 49.5% reported reduced sleep while 12.8% reported poor quality sleep. Factors significantly (p<0.05) associated with poor quality sleep were: often feeling stressed or anxious (OR=5.49), being born in Mexico (OR=0.65), using a computer/playing video games 15+ hours per week (OR=2.29), working (OR=1.37), being a current smoker (OR=2.16), and being a current alcohol user (OR=1.64). Factors significantly associated with reduced quantity of sleep were: often feeling stressed or anxious (OR=2.74), often having headaches/stomachaches (OR=1.77), being a current marijuana user (OR=1.70), being a current methamphetamine user (OR=4.92), and being a current alcohol user (OR=1.27). ^ Discussion. Previous research suggests that there are several factors that can influence sleep quality and quantity in adolescents. This paper discusses these factors (i.e. work, smoking, alcohol, etc.) found to be associated with poor sleep quality and reduced sleep quantity in the Hispanic adolescent population. A reduced quantity of sleep (81.20% of the participants) and a poor quality of sleep (12.80% of the participants) were also found in high school students from South Texas. ^

Molecular dissolved organic matter composition and environmental parameters from a laboratory incubation study

Dissolved organic matter (DOM) in the oceans constitutes a major carbon pool involved in global biogeochemical cycles. More than 96% of the marine DOM resists microbial degradation for thousands of years. The composition of this refractory DOM (RDOM) exhibits a molecular signature which is ubiquitously detected in the deep oceans. Surprisingly efficient microbial transformation of labile into RDOM was shown experimentally, implying that microorganisms produce far more RDOM than needed to sustain the global pool. By assessing the microbial formation and transformation of DOM in unprecedented molecular detail for 3 years, we show that most of the newly formed RDOM is molecularly different from deep sea RDOM. Only <0.4% of the net community production was channeled into RDOM molecularly undistinguishable from deep sea DOM. Our study provides novel experimentally derived molecular evidence and data for global models on the production, turnover and accumulation of marine DOM.

Organic matter C and N composition and N. pachyderma stable isotope ratios of ODP Hole 188-1166A sediments

We report the results of downhole stable isotopic (d13Corg [organic carbon] and d15N) and elemental measurements (total organic carbon [TOC], total nitrogen [TN], and carbon/nitrogen [C/N]) of sedimentary organic matter (SOM) along with stable isotopic measurements (d18O and d13C) of left-coiling Neogloboquadrina pachyderma planktonic foraminifers from Ocean Drilling Program Site 1166. TOC and TN measurements indicate a large change from organic-rich preglacial sediments with primary organic matter to organic-poor early glacial and glacial sediments, with mainly recycled organic matter. Results of the stable isotopic measurements of SOM show a range of values that are typical of both marine and terrestrial organic matter, probably reflecting a mixture of the two. However, C/N values are mostly high (>15), suggesting greater input and/or preservation of terrestrial organic matter. Foraminifers are only present in glacial/glaciomarine sediments of latest Pliocene to Pleistocene age at Site 1166 (lithostratigraphic Unit I). The majority of this unit has d13Corg and TOC values that are similar to those of glacial sediments recovered at Site 1167 (lithostratigraphic Unit II) on the slope and may have the same source(s). Although the low resolution of the N. pachyderma (s.) d18O and d13C data set precludes any specific paleoclimatic interpretation, downcore variations in foraminifer d18O and d13C values of 0.5 per mil to 1 per mil amplitude may indicate glacial-interglacial changes in ice volume/temperature in the Prydz Bay region.

Carbon dioxide assimilation rate, gas and ion composition in samples, and bacterial production of organic matter within and above the Broken Spur and TAG hydrothermal fields, Mid-Atlantic Ridge

Rate of CO2 assimilation was determined above the Broken Spur and TAG active hydrothermal fields for three main ecosystems: (1) hydrothermal vents; (2) 300 m near-bottom layer of plume water; and (3) bottom sediments. In water samples from warm (40-45°C) vents assimilation rates were maximal and reached 2.82-3.76 µg C/l/day. In plume waters CO2 assimilation rates ranged from 0.38 to 0.65 µg C/l/day. In bottom sediments CO2 assimilation rates varied from 0.8 to 28.0 µg C/l/day, rising up to 56 mg C/kg/day near shrimp swarms. In the most active plume zone of the long-living TAG field bacterial production of organic matter (OM) from carbonic is up to 170 mg C/m**2/day); production of autotrophic process of bacterial chemosynthesis reaches about 90% (156 mg C/m**2/day). Thus, chemosynthetic production of OM in September-October is almost equal to that of photosynthetic production in the oceanic region. Bacterial production of OM above the Broken Spur hydrothermal field is one order lower and reaches only 20 mg C/m**2/day.

A model to improve the quality and quantity of minority student participation in vocational-technical education programs /

A model program implemented at Dawson Technical Institute in Chicago.

The use of quality and quantity of publication as criteria for evaluating scientists,

Cover title.