Temporal shifts in physical habitat of the crayfish,Orconectes neglectus (Faxon)

A total of 300 samples was collected from February 1985 to August 1986 in a medium order Ozark Mountain stream. Physical habitat measurements of temperature, mean water column velocity, depth, and substrate character were recorded for each of the 25 monthly samples along with length and sex of all individuals of Orconectes neglectus (Faxon). Analysis of habitat utilization and suitability (or preference) was conducted using exponential polynomial models of hydraulic stress models. There appeared to be equal preference for depth over the range measured. Both substrate and velocity preference curves were bimodal with each mode designating certain crayfish size classes. Young-of-the-year were found primarily in cobbled, high velocity areas while adults were found in low velocity, macrophyte beds. Utilization curves for laminar sublayer thichness also reflected size-dependent phenomena where young-of-the-year were found in thin sublayer areas and adults were found primarily in thick sublayers. When separated by time and size, adults were found to occupy higher velocity, cobbled habitats during at least two months. This time period corresponded with the time of egg-bearing and further analysis yielded a time-dependent habitat suitability surface which accounted for this movement pattern. We suggest that the application of these suitability surfaces, which reflect habitat changes during the annual life cycle, will produce more accurate predictions of density and will allow better habitat management decisions under various regulated flow scenarios.     

Transversus abdominis activation during a side-bridge exercise progression is similar in people with recurrent low back pain and healthy controls

ABSTRACT: Himes, MA, Selkow, NM, Gore, MA, Hart, JM, Saliba, SA. Transversus abdominis activation during a side-bridge exercise progression is similar in people with recurrent low back pain and healthy controls. J Strength Cond Res 26(11): 3106-3112, 2012-Low back pain (LBP) affects 70-80% of the population. The transversus abdominis (TrA) has been implicated as part of the cause of LBP. Prevention and rehabilitation of LBP often target the TrA using exercises such as the side bridge accompanied with the abdominal drawing-in maneuver (ADIM). However, it is unknown whether individuals with recurrent LBP, when they are in a period of no pain, are able to activate the TrA and healthy individuals during this exercise. The purpose of our study was to compare the activation ratio of the TrA during a 5-level side-bridge exercise progression. Twenty-three subjects with a history of recurrent, nonspecific LBP, but not experiencing an exacerbation of symptoms and 24 healthy controls volunteered. All the subjects performed the ADIM and side-bridge exercises with clinician feedback (verbal cueing). Each participant performed the side-bridge exercise progression while ultrasound images were taken. The subjects were only progressed if they successfully completed the previous level. The thickness of the TrA was measured in rested and contracted states at each exercise level to find the activation ratio (TrA contracted/TrA rest). Separate analyses of covariance did not reveal a difference in activation ratios between groups (p > 0.40) when the ratio at the lowest level was used as the covariate. The results from this study indicate that both groups were able to contract the TrA with verbal cueing during a side-bridge exercise progression. Because the TrA contracted similarly during exercise in both groups, the association of LBP with the TrA may be because of another mechanism, such as delayed activation in the feed-forward mechanism during activity or a lack of endurance of the TrA.     

Long-term survival of patients with breast cancer: a study of the curability of the disease.

A retrospective analysis was made of 3878 cases of breast carcinoma first seen in Edinburgh from 1954 to 1964. During this time there was a policy to treat breast cancer by simple mastectomy and x-ray therapy, and over 90% of cases classified as international stages I and II were so treated. The mortality in these women was compared with that in an equivalent normal population using Scottish national age-specific death rates. For every year of follow-up within 20 years of initial treatment there was an excess mortality from all causes. There was an overall excess mortality of 58% among patients with breast cancer 15-20 years after initial treatment, and 20 times more deaths occurred in this period from breast cancer than in a normal population. For patients disease-free after 15 years there was still a 28% excess mortality from all causes. Factors known to be of major prognostic significance for five-year survivorship had less influence than might have been expected when the ratio of observed to expected deaths was considered for longer periods of follow-up. The effect of clinical staging (I, II, or III), though initially marked, largely disappeared by the 10th year of follow-up, and after allowing for age there was no evidence beyond 10 years of an effect on survival of the original stage of the disease. Similarly, the effect of tumour size on survival disappeared after 10 years. Women who were premenopausal at presentation still had a significant excess of deaths in the fourth quinquennium of follow-up. In the menopausal and postmenopausal groups combined there was still a small non-significant excess of deaths from all causes after 15 years but this almost disappeared when patients who had already relapsed were excluded. In terms of overall mortality only patients who have undergone the menopause before presentation and who are disease-free 15 years after primary treatment may prove to be cured by conventional techniques such as simple mastectomy and postoperative radiotherapy.     

Caribbean corals in crisis: record thermal stress, bleaching, and mortality in 2005

Background

The rising temperature of the world''s oceans has become a major threat to coral reefs globally as the severity and frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropical Atlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin.

Methodology/Principal Findings

Satellite-based tools provided warnings for coral reef managers and scientists, guiding both the timing and location of researchers'' field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior efforts in detail and extent, and provided a new standard for documenting the effects of bleaching and for testing nowcast and forecast products. Collaborators from 22 countries undertook the most comprehensive documentation of basin-scale bleaching to date and found that over 80% of corals bleached and over 40% died at many sites. The most severe bleaching coincided with waters nearest a western Atlantic warm pool that was centered off the northern end of the Lesser Antilles.

Conclusions/Significance

Thermal stress during the 2005 event exceeded any observed from the Caribbean in the prior 20 years, and regionally-averaged temperatures were the warmest in over 150 years. Comparison of satellite data against field surveys demonstrated a significant predictive relationship between accumulated heat stress (measured using NOAA Coral Reef Watch''s Degree Heating Weeks) and bleaching intensity. This severe, widespread bleaching and mortality will undoubtedly have long-term consequences for reef ecosystems and suggests a troubled future for tropical marine ecosystems under a warming climate.     

Development of a bladder instillation of the indoloquinone anticancer agent EO-9 using tert-butyl alcohol as lyophilization vehicle

The purpose of this research was to develop a stable bladder instillation of EO-9 for the treatment of superficial bladder cancer. First, stability and dissolution studies were performed. Subsequently, the freeze-drying process was optimized by determination of the freeze-drying characteristics of the selected cosolvent/water system and differential scanning calorimetry analysis of the formulation solution. Furthermore, the influence of the freeze-drying process on crystallinity and morphology of the freeze-dried product was determined with x-ray diffraction analysis and scanning electron microscopy, respectively. Subsequently, a reconstitution solution was developed. This study revealed that tert-butyl alcohol (TBA) can be used to both dramatically improve the solubility and stability of EO-9 and to shorten the freeze-drying cycle by increasing the sublimation rate. During freeze drying, 3 TBA crystals were found: TBA hydrate-ice crystals, crystals of TBA hydrate, and a third crystal, probably composed of TBA hydrate crystals containing ≈90% to 95% TBA. Furthermore, it was shown that crystallization of TBA hydrate was inhibited in the presence of both sodium bicarbonate (NaHCO₃) and mannitol. Addition of an annealing step resulted in a minor increase in the crystallinity of the freeze-dried product and formation of the δ-polymorph of mannitol. A stable bladder instillation was obtained after reconstitution of the freeze-dried product (containing 8 mg of EO-9, 20 mg of NaHCO₃, and 50 mg of mannitol per vial) to 20 mL with a reconstitution solution composed of propylene glycol/water for injection (WfI)/NaHCO₃/sodium edetate 60%/40%/2%/0.02% vol/vol/wt/wt, followed by dilution with Wfl to a final volume of 40 mL. Published: August 3, 2007     

Extremity hyperinsulinemia stimulates muscle protein synthesis in severely injured patients

Insulin has a well-recognized anabolic effect on muscle protein, yet critically ill, severely injured patients are often considered "resistant" to the action of insulin. The purpose of this study was to assess the in vivo effects of hyperinsulinemia on human skeletal muscle in severely injured patients. To accomplish this goal, 14 patients with burns encompassing >40% of their body surface area underwent metabolic evaluation utilizing isotopic dilution of phenylalanine, femoral artery and vein blood sampling, and sequential muscle biopsies of the leg. After baseline metabolic measurements were taken, insulin was infused into the femoral artery at 0.45 mIU.min(-1).100 ml leg volume(-1) to create a local hyperinsulinemia but with minimal systemic perturbations. Insulin administration increased femoral venous concentration of insulin (P < 0.01) but with only a 4% (insignificant) decrease in the arterial glucose concentration and a 7% (insignificant) decrease in the arterial concentration of phenylalanine. Extremity hyperinsulinemia significantly increased leg blood flow (P < 0.05) and the rate of muscle protein synthesis (P < 0.05). Neither the rate of muscle protein breakdown nor the rate of transmembrane transport of phenylalanine was significantly altered with extremity hyperinsulinemia. In conclusion, this study demonstrates that insulin directly stimulates muscle protein synthesis in severely injured patients.     

Aberrant epigenetic and genetic marks are seen in myelodysplastic leukocytes and reveal Dock4 as a candidate pathogenic gene on chromosome 7q

Myelodysplastic syndromes (MDS) are characterized by abnormal and dysplastic maturation of all blood lineages. Even though epigenetic alterations have been seen in MDS marrow progenitors, very little is known about the molecular alterations in dysplastic peripheral blood cells. We analyzed the methylome of MDS leukocytes by the HELP assay and determined that it was globally distinct from age-matched controls and was characterized by numerous novel, aberrant hypermethylated marks that were located mainly outside of CpG islands and preferentially affected GTPase regulators and other cancer-related pathways. Additionally, array comparative genomic hybridization revealed that novel as well as previously characterized deletions and amplifications could also be visualized in peripheral blood leukocytes, thus potentially reducing the need for bone marrow samples for future studies. Using integrative analysis, potentially pathogenic genes silenced by genetic deletions and aberrant hypermethylation in different patients were identified. DOCK4, a GTPase regulator located in the commonly deleted 7q31 region, was identified by this unbiased approach. Significant hypermethylation and reduced expression of DOCK4 in MDS bone marrow stem cells was observed in two large independent datasets, providing further validation of our findings. Finally, DOCK4 knockdown in primary marrow CD34(+) stem cells led to decreased erythroid colony formation and increased apoptosis, thus recapitulating the bone marrow failure seen in MDS. These findings reveal widespread novel epigenetic alterations in myelodysplastic leukocytes and implicate DOCK4 as a pathogenic gene located on the 7q chromosomal region.     

Has Armstrong's cycle efficiency improved?

This case describes the physiological maturation from ages 21 to 28 yr of the bicyclist who has now become the six-time consecutive Grand Champion of the Tour de France, at ages 27-32 yr. Maximal oxygen uptake (Vo(2max)) in the trained state remained at approximately 6 l/min, lean body weight remained at approximately 70 kg, and maximal heart rate declined from 207 to 200 beats/min. Blood lactate threshold was typical of competitive cyclists in that it occurred at 76-85% Vo(2max), yet maximal blood lactate concentration was remarkably low in the trained state. It appears that an 8% improvement in muscular efficiency and thus power production when cycling at a given oxygen uptake (Vo(2)) is the characteristic that improved most as this athlete matured from ages 21 to 28 yr. It is noteworthy that at age 25 yr, this champion developed advanced cancer, requiring surgeries and chemotherapy. During the months leading up to each of his Tour de France victories, he reduced body weight and body fat by 4-7 kg (i.e., approximately 7%). Therefore, over the 7-yr period, an improvement in muscular efficiency and reduced body fat contributed equally to a remarkable 18% improvement in his steady-state power per kilogram body weight when cycling at a given Vo(2) (e.g., 5 l/min). It is hypothesized that the improved muscular efficiency probably reflects changes in muscle myosin type stimulated from years of training intensely for 3-6 h on most days.