Skeletal muscle cells lacking the retinoblastoma protein display defects in muscle gene expression and accumulate in S and G2 phases of the cell cycle.

Viral oncoproteins that inactivate the retinoblastoma tumor suppressor protein (pRb) family both block skeletal muscle differentiation and promote cell cycle progression. To clarify the dependence of terminal differentiation on the presence of the different pRb-related proteins, we have studied myogenesis using isogenic primary fibroblasts derived from mouse embryos individually deficient for pRb, p107, or p130. When ectopically expressed in fibroblasts lacking pRb, MyoD induces an aberrant skeletal muscle differentiation program characterized by normal expression of early differentiation markers such as myogenin and p21, but attenuated expression of late differentiation markers such as myosin heavy chain (MHC). Similar defects in MHC expression were not observed in cells lacking either p107 or p130, indicating that the defect is specific to the loss of pRb. In contrast to wild-type, p107-deficient, or p130-deficient differentiated myocytes that are permanently withdrawn from the cell cycle, differentiated myocytes lacking pRb accumulate in S and G2 phases and express extremely high levels of cyclins A and B, cyclin-dependent kinase (Cdk2), and Cdc2, but fail to readily proceed to mitosis. Administration of caffeine, an agent that removes inhibitory phosphorylations on inactive Cdc2/cyclin B complexes, specifically induced mitotic catastrophe in pRb-deficient myocytes, consistent with the observation that the majority of pRb-deficient myocytes arrest in S and G2. Together, these findings indicate that pRb is required for the expression of late skeletal muscle differentiation markers and for the inhibition of DNA synthesis, but that a pRb-independent mechanism restricts entry of differentiated myocytes into mitosis

Topical Menthol, Ice, Peripheral Blood Flow, and Perceived Discomfort

Context : Injury management commonly includes decreasing arterial blood flow to the affected site in an attempt to reduce microvascular blood flow and edema and limit the induction of inflammation. Applied separately, ice and menthol gel decrease arterial blood flow, but the combined effects of ice and menthol gel on arterial blood flow are unknown. Objectives : To compare radial artery blood flow, arterial diameter, and perceived discomfort before and after the application of 1 of 4 treatment conditions. Design : Experimental crossover design. Setting : Clinical laboratory. Participants or Other Participants : Ten healthy men, 9 healthy women (mean age = 25.68 years, mean height = 1.73 m, mean weight = 76.73 kg). Intervention(s) : Four treatment conditions were randomly applied for 20 minutes to the right forearm of participants on 4 different days separated by at least 24 hours: (1) 3.5 mL menthol gel, (2) 0.5 kg of crushed ice, (3) 3.5 mL of menthol gel and 0.5 kg of crushed ice, or (4) no treatment (control). Main Outcome Measure(s) : Using high-resolution ultrasound, we measured right radial artery diameter (cm) and blood flow (mL/min) every 5 minutes for 20 minutes after the treatment was applied. Discomfort with the treatment was documented using a 1-to-10 intensity scale. Results : Radial artery blood flow decreased (P \u3c .05) from baseline in the ice (−20% to −24%), menthol (−17% to −24%), and ice and menthol (−36% to −39%) treatments but not in the control (3% to 9%) at 5, 10, and 15 minutes. At 20 minutes after baseline, only the ice (−27%) and combined ice and menthol (−38%) treatments exhibited reductions in blood flow (P \u3c .05). Discomfort was less with menthol than with the ice treatment at 5, 10, and 20 minutes after application (P \u3c .05). Arterial diameter and heart rate did not change. Conclusions : The application of 3.5 mL of menthol was similar to the application of 0.5 kg of crushed ice in reducing peripheral blood flood. Combining crushed ice with menthol appeared to have an additive effect on reducing blood flow

Prediction of VO\u3csub\u3e2\u3c/sub\u3e Peak Using Sub-Maximum Bench Step Test in Children

The purpose of this study was to develop a valid prediction of maximal oxygen uptake from data collected during a submaximum bench stepping test among children ages 8-12 years. Twentyseven active subjects (16 male and 11 female), weight 36.1 kg, height 144.4 cm and VO2 47.4 ± 7.9 ml/kg/min participated. Subjects completed a maximal oxygen consumption test with analysis of expired air and a submaximal bench stepping test. A formula to predict VO2max was developed from height, resting heart rate and heart rate response during the submaximum bench stepping test. This formula accounted for 71% of the variability in maximal oxygen consumption and is the first step in verifying the validity of the submaximum bench stepping test to predict VO2max. VO2max = -2.354 + (Height in cm * 0.065) + (Resting Heart Rate * 0.008) + (Step Test Average Heart Rate as a Percentage of Resting Heart Rate * -0.870

A proposed typology of online hate crime

Hate offenders and those convicted of ‘radical’ or ‘extremist’ terror-related offences have a well-established presence online, and hate incidents which occur in the real world are increasingly being linked to online ‘virtual’ activities (INCAH, 2010). Building on psychological research and theory, in particular McDevitt, Levin, and Bennett (2002), and Gerstenfeld, Grant, and Chang (2003), this study has developed an original typology of online hate offending, dividing it into four distinct types of user: Browsers, Commentators, Activists, and Leaders. In a partial test of this typology, an online search was conducted for hate incidents relating to a single London borough over seven months. The search uncovered a wide variety of online incidents. Content and thematic analysis supported the division of the typology into four distinct superordinate themes. Amendments to the typology and recommendations are then discussed

Roles, Responsibilities, Celebrations, and Post-Presidency Aspirations of Female College Presidents

Of the 3,300 university and college presidents in higher education in the United States, only 23% are held by females (The Chronicle of Higher Education, 2007). The percentage of female students in most institutions in higher education is higher than those of male students. The Central questions that guided this research study are as follows: What are the roles and responsibilities of presidents of higher educational institutions? How do presidents of higher education celebrate their professional and personal accomplishments? Additionally, what are the post-presidency aspirations of the eight women interviewed who all currently are in their first presidency position in either a private or public four-year institution? Qualitative research methods were used for this study. The collective case study tradition (Creswell, 2003) was used in order to capture thick, rich descriptions of the cases. Eight female college presidents in their first presidency participated in the study. Interviews, documents, and observations were collected and included in the data analysis. Within-case analyses were conducted for each participant, followed by a cross-analysis, with major themes emerging. While feminist leadership theories and culture theory were used as a lens and guided the current research, themes emerged from the study that may assist future women as they pursue presidencies in the future. Nine conclusions are presented that relate to the themes that emerged for each secondary research question. The nine conclusions were determined based on the research findings. The conclusions relate to the areas of interest for women in presidencies and/or seeking a presidency which are summarized as follows: (1) Becoming the Institution; (2) Understanding the Financial Complexities; (3) Involvement in Community, State, Regional, National Associations; (4) Family and Personal Responsibilities; (5) Professional Sacrifices; (6) Family and Personal Sacrifices; (7) Celebrations of Accomplishments; (8) Post-Presidency Aspirations; (9) Strategies for Post-Presidency Plans. Recommendations for females who aspire to become a president are detailed. Suggestions for future research are presented

Redox Reactions in Groundwater with Health Implications

Mobilisation into groundwater of many trace elements are redox dependant and of health concern. A short list includes arsenic, manganese, chromium, selenium, nitrogen as nitrate and uranium. Arsenic is mobile in groundwater essentially under two conditions, under reducing conditions mobilising ferrous iron and arsenite and at high pH when the ferric oxyhydroxides lose their positive charge. Manganese is mobilised under moderately reducing conditions as Mn2+ and might affect the mental capacity at chronic exposure from drinking water. Chromium is mobile as carcinogenic chromate under oxidising conditions. Manganese oxides may oxidise Cr(III) solids. Chromium may come from natural as well as anthropogenic sources. Selenium, an essential element, rarely exceeds permissible limits but irrigation with groundwater with elevated selenium could cause toxic selenium intake via food. Selenium is mobile in groundwater under oxidising conditions. Nitrate from excess use of fertilisers may be a problem for bottle-fed children below the age of 1 year, forming methaemoglobinemia. Uranium is mobile under oxidising conditions as U(VI). Mobility and toxicity depends on numerous factors. The threat from uranium is its effect on the readsorption in the kidney of water and salts from the primary urine. Oxidation state and speciation govern uranium mobility