Radiometrical, hormonal and biological correlates of skeletal growth in the female rat from birth to senescence

OBJECTIVE We investigated the skeletal growth profile of female rats from birth to senescence (100weeks) on the basis of sequential radiometrical, hormonal and biochemical parameters. DESIGN Weaning rats entered the study which was divided into two sections: a) sequential measurements of vertebral and tibial growths and bone mineral density (BMD), estimation of mineral content of the entire skeleton (BMC) and chemical analysis of vertebral Ca; and b) determination of basal and pulsatile growth hormone (rGH), insulin-like growth hormone (IGF-I), estradiol (E2), parathyroid hormone (PTH), osteocalcin (OC) and urinary d-pyridinoline (dp) throughout the experimental period. RESULTS Vertebral and tibial growths ceased at week 25 whereas BMD and BMC as well as total vertebral Ca exhibited a peak bone mass at week 40. rGH pulsatile profiles were significantly higher in younger animals coinciding with the period of active growth and IGF-I peaked at 7weeks, slowly declining thereafter and stabilizing after week 60. OC and dp closely paralleled IGF-I coinciding with the period of enhanced skeletal growth, remaining thereafter in the low range indicative of reduced bone turnover. E2 increased during reproductive life but the lower values subsequently recorded were still in the physiological range, strongly suggesting a protective role of this steroid on bone remodeling. PTH followed a similar profile to E2, but the significance of this after completion of growth remains unclear. CONCLUSIONS Mechanisms governing skeletal growth in the female rat appear similar to those in humans. Bone progression and attainment of peak bone mass are under simultaneous control of rGH, IGF-I and calciotropic hormones and are modulated by E2. This steroid seems to protect the skeleton from resorption before senescence whereas the role of PTH in this context remains uncertain.

Late-glacial and Holocene vegetation history and dynamics as shown by pollen and plant macrofossil analyses in annually laminated sediments from Soppensee, central Switzerland

The palynostratigraphy of two sediment cores from Soppensee, Central Switzerland (596 m asl) was correlated with nine regional pollen assemblage zones defined for the Swiss Plateau. This biostratigraphy shows that the sedimentary record of Soppensee includes the last 15 000 years, i.e. the entire Late-glacial and Holocene environmental history. The vegetation history of the Soppensee catchment was inferred by pollen and plant-macrofossil analyses on three different cores taken in the deepest part of the lake basin (27 m). On the basis of a high-resolution varve and calibrated radiocarbonchronology it was possible to estimate pollen accumulation rates, which together with the pollen percentage data, formed the basis for the interpretation of the past vegetation dynamics. The basal sediment dates back to the last glacial. After reforestation with juniper and birch at ca. 12 700 B.P., the vegetation changed at around 12 000 B.P. to a pine-birch woodland and at the onset of the Holocene to a mixed deciduous forest. At ca. 7000 B.P., fir expanded and dominated the vegetation with beech becoming predominant at ca. 50014C-years later until sometime during the Iron Age. Large-scale deforestation, especially during the Middle Ages, altered the vegetation cover drastically. During the Late-glacial period two distinct regressive phases in vegetation development are demonstrated, namely, the Aegelsee oscillation (equivalent to the Older Dryas biozone) and the Younger Dryas biozone. No unambiguous evidence for Holocene climatic change was detected at Soppensee. Human presence is indicated by early cereal pollen and distinct pulses of forest clearance as a result of human activity can be observed from the Neolithic period onwards.

Effects of Estrogen on Muscle Damage in Response to an Acute Resistance Exercise Protocol

Creatine Kinase (CK) is used as a measure of exercise-induced muscle membrane damage. During acute eccentric (muscle lengthening) exercise, muscle sarcolemma, sarcoplasmic reticulum, and Z-lines are damaged, thus causing muscle proteins and enzymes to leak into the interstitial fluid. Strenuous eccentric exercise produces an elevation of oxygen free radicals, which further increases muscle damage. Muscle soreness and fatigue can be attributed to this membrane damage. Estradiol, however, may preserve membrane stability post-exercise (Brancaccio, Maffulli, & Limongelli, 2007; Carter, Dobridge, & Hackney, 2001; Tiidus, 2001). Because estradiol has a similar structure to Vitamin E, which is known to have antioxidant properties, and both are known to affect membrane structure, researchers have proposed that estrogen acts as an antioxidant to provide a protective effect on the post-exercise muscle of women (Sandoval & Matt, 2002). As a result, it has been postulated that muscles in women incur less damage in response to an acute strenuous exercise as compared to men. PURPOSE: To determine if circulating estrogen concentrations are related to muscle damage, as measured by creatine kinase activity and to determine gender differences in creatine kinase as a marker of muscle damage in response to an acute heavy resistance exercise protocol. METHODS: 7 healthy, resistance-trained, eumenhorrheic women (23±3 y, 169±9.1 cm, 66.4±10.5 kg) and 8 healthy, resistance-trained men (25±5 y, 178±6.7 cm, 82.3±9.33 kg) volunteered to participate in the study. Subjects performed an Acute Resistance Exercise Test (ARET) consisting of 6 sets of 5 repetitions Smith machine squats at 90% of their previously determined 1-RM. Blood samples were taken pre-, mid-, post-, 1 hour post-, 6 hours post-, and 24 hours post-exercise. Samples were stored at -80ºC until analyzed. Serum creatine kinase was measured using an assay kit from Genzyme (Framingham, MA). Serum estradiol was measured by an ELISA from GenWay (San Diego, CA). Estradiol b-receptor presence on granulocytes was measured via flow cytometry using primary antibodies from Abcam (Cambridge, MA) and PeCy7 antibodies (secondary) from Santa Cruz (Santa Cruz, CA). RESULTS: No significant correlations between estrogen and CK response were found after an acute resistant exercise protocol. Moreover, no significant change in estradiol receptors were expressed on granulocytes after exercise. Creatine Kinase response, however, differed significantly between genders. Men had higher resting CK concentrations throughout all time points. Creatine Kinase response increased significantly after exercise in both men and women (p=0.008, F=9.798). Men had a significantly higher CK response at 24 hours post exercise than women. A significant condition/sex/time interaction was exhibited in CK response (p=0.02, F=4.547). Perceived general soreness presented a significant condition, sex interaction (p=0.01, F=9.532). DISCUSSION: Although no estradiol and CK response correlations were found in response to exercise, a significant difference in creatine kinase activity was present between men and women. This discrepancy of our results and findings in the literature may be due to the high variability between subjects in creatine kinase activity as well as estrogen concentrations. The lack of significance in change of estradiol receptor expression on granulocytes in response to exercise may be due to intracellular estradiol receptor staining and non-specific gating for granulocytes rather than additional staining for neutrophil markers. Because neutrophils are the initial cells present in the inflammatory response after strenuous exercise, staining for estrogen receptors on this cell type may allow for a better understanding of the effect of estrogen and its hypothesized protective effect against muscle damage. Furthermore, the mechanism of action may include estradiol receptor expression on the muscle fiber itself may play a role in the protective effects of estradiol rather than or in addition to expression on neutrophils. We have shown here that gender differences occur in CK activity as a marker of muscle damage in response to strenuous eccentric exercise, but may not be the result of estradiol concentration or estradiol receptor expression on granulocytes. Other variables should be examined in order to determine the mechanism involved in the difference in creatine kinase as a marker of muscle damage between men and women after heavy resistance exercise.

Elimination of racial/ethnic Hepatitis B vaccination disparities in the US in the 2007--2008 National Health and Nutrition Examination Survey

Viral hepatitis is a significant public health problem worldwide and is due to viral infections that are classified as Hepatitis A, B, C, D, and E. Hepatitis B is one of the five known hepatic viruses. A safe and effective vaccine for Hepatitis B was first developed in 1981, and became adopted into national immunization programs targeting infants since 1990 and adolescents since 1995. In the U.S., this vaccination schedule has led to an 82% reduction in incidence from 8.5 cases per 100,000 in 1990 to 1.5 cases per 100,000 in 2007. Although there has been a decline in infection among adolescents, there is still a large burden of hepatitis B infection among adults and minorities. There is very little research in regards to vaccination gaps among adults. Using the National Health and Nutrition Examination Survey (NHANES) question "{Have you/Has SP (Study Participant)} ever received the 3-dose series of the hepatitis B vaccine?" the existence of racial/ethnic gaps using a cross-sectional study design was explored. In this study, other variables such as age, gender, socioeconomic variables (federal poverty line, educational attainment), and behavioral factors (sexual practices, self-report of men having sex with men, and intravenous drug use) were examined. We found that the current vaccination programs and policies for Hepatitis B had eliminated racial and ethnic disparities in Hepatitis B vaccination, but that a low coverage exists particularly for adults who engage in high risk behaviors. This study found a statistically significant 10% gap in Hepatitis B vaccination between those who have and those who do not have access to health insurance.^

Foraminifer counts in core JM01-1199, and review of radiocarbon ages in the Norwegian-Barents Sea-Svalbard margin

We compare six high-resolution Holocene, sediment cores along a S-N transect on the Norwegian-Svalbard continental margin from ca 60°N to 77.4°N, northern North Atlantic. Planktonic foraminifera in the cores were investigated to show the changes in upper surface and subsurface water mass distribution and properties, including summer sea-surface temperatures (SST). The cores are located below the axis of the Norwegian Current and the West Spitsbergen Current, which today transport warm Atlantic Water to the Arctic. Sediment accumulation rates are generally high at all the core sites, allowing for a temporal resolution of 10-102 years. SST is reconstructed using different types of transfer functions, resulting in very similar SST trends, with deviations of no more than +- 1.0/1.5 °C. A transfer function based on the maximum likelihood statistical approach is found to be most relevant. The reconstruction documents an abrupt change in planktonic foraminiferal faunal composition and an associated warming at the Younger Dryas-Preboreal transition. The earliest part of the Holocene was characterized by large temperature variability, including the Preboreal Oscillations and the 8.2 k event. In general, the early Holocene was characterized by SSTs similar to those of today in the south and warmer than today in the north, and a smaller S-N temperature gradient (0.23 °C/°N) compared to the present temperature gradient (0.46 °C/°N). The southern proxy records (60-69°N) were more strongly influenced by slightly cooler subsurface water probably due to the seasonality of the orbital forcing and increased stratification due to freshening. The northern records (72-77.4°N) display a millennial-scale change associated with reduced insolation and a gradual weakening of the North Atlantic thermohaline circulation (THC). The observed northwards amplification of the early Holocene warming is comparable to the pattern of recent global warming and future climate modelling, which predicts greater warming at higher latitudes. The overall trend during mid and late Holocene was a cooling in the north, stable or weak warming in the south, and a maximum S-N SST gradient of ca 0.7 °C/°N at 5000 cal. years BP. Superimposed on this trend were several abrupt temperature shifts. Four of these shifts, dated to 9000-8000, 5500-3000 and 1000 and ~400 cal. years BP, appear to be global, as they correlate with periods of global climate change. In general, there is a good correlation between the northern North Atlantic temperature records and climate records from Norway and Svalbard.

Elaboración artesanal de mermeladas de tres ecotipos de tuna (Opuntia ficus indica f. inerme) roja, anaranjada y verde

La tuna es una fruta presente principalmente en zonas áridas y semiáridas. Su aporte nutricional podría aprovecharse consumiéndola en forma directa, como así también a través de productos elaborados en forma artesanal. Dichos productos podrían incorporarse a la economía del mercado de consumo interno y eventualmente externo. Por tal motivo, se evalúa la posibilidad de desarrollar mermeladas con tres ecotipos de tuna de la misma variedad, considerando la aceptación del producto. Se trabajó con tunas (Opuntia ficus indica f. inerme), cultivadas en el Centro Regional de Investigaciones Científicas y Tecnológicas (CRICYT) ubicado en el Parque General San Martín, Capital, Mendoza. El objetivo general del trabajo estuvo dirigido a la elaboración de mermeladas de tres ecotipos de tuna: tuna roja o morada, tuna anaranjada o amarilla y tuna verde o blanca acorde a la legislación vigente. Los ítems específicos estuvieron conducidos hacia el desarrollo de una mermelada utilizando una fruta no convencional, para determinar el valor nutricional del mismo, y sus características fisicoquímicas, ampliar la producción de subproductos de tuna en la región árida y semiárida, para así finalmente evaluar el grado de aceptabilidad sensorial y comercial del producto. Se caracterizaron los tres ecotipos de tuna y sus respectivas mermeladas mediante determinaciones fisicoquímicas, se verificó el contenido nutricional y se realizaron los análisis microbiológicos de cada una de ellas. Dentro de las determinaciones fisicoquímicas de las mermeladas se incluyó K, P, Ca y vitamina C, teniendo en cuenta que se parte de una materia prima con buenas cantidades de estos minerales y vitamina C con respecto a otras frutas. Se llevaron a cabo pruebas de evaluación sensorial del producto terminado y se consultó el precio que estarían dispuestos a pagar los potenciales consumidores. Los jueces entrenados contribuyeron al diseño de un perfil sensorial para cada una de las mermeladas y evaluaron en forma global al producto obtenido. Los resultados obtenidos en cuanto a la caracterización de la materia prima arrojan un buen contenido en sólidos solubles, vitamina C y en minerales como el fósforo, calcio, potasio y un contenido bajo en sodio con respecto a otras frutas que se consumen habitualmente. Los análisis microbiológicos realizados para evaluar la conservación permiten expresar que se trata de un producto de bajo riesgo microbiológico, bajo las condiciones de conservación que se obtuvieron. En base a lo expuesto, se puede concluir que es técnicamente posible elaborar artesanalmente mermeladas de tres ecotipos de tuna, las cuales poseen un buen aporte nutricional, son aptas para el consumo humano desde el punto de vista bromatológico y aceptadas sensorialmente por los consumidores.

Conflicto político, demografía y modo de producción en la Antigua Roma, siglos II-I a.C

Este trabajo se propone analizar críticamente algunas teorías recientes sobre las consecuencias sociales de la Segunda Guerra Púnica (218-201 a. C.) en la antigua sociedadáromana. Mientras que laáinterpretación clásica había subrayado el efecto dañino que las guerras de expansión supusieronápara el campesinado romano, los nuevos enfoques en boga se caracterizan por dejar de lado las contradicciones del proceso histórico, adoptando una interpretación malthusiana en la cual laápoblación simplementeáhabría crecido mucho más que los recursos para sostenerla. Considerando que la demografía no es una variable independiente sino que se encuentra enmarcada en un modo de producción específico, se propone estudiar algunasálimitaciones de los enfoques mencionados paraáluego abordar el problema desde una óptica que enfatice en la dinámica contradictoria de la sociedad romana

Conflicto político, demografía y modo de producción en la Antigua Roma, siglos II-I a.C

Este trabajo se propone analizar críticamente algunas teorías recientes sobre las consecuencias sociales de la Segunda Guerra Púnica (218-201 a. C.) en la antigua sociedadáromana. Mientras que laáinterpretación clásica había subrayado el efecto dañino que las guerras de expansión supusieronápara el campesinado romano, los nuevos enfoques en boga se caracterizan por dejar de lado las contradicciones del proceso histórico, adoptando una interpretación malthusiana en la cual laápoblación simplementeáhabría crecido mucho más que los recursos para sostenerla. Considerando que la demografía no es una variable independiente sino que se encuentra enmarcada en un modo de producción específico, se propone estudiar algunasálimitaciones de los enfoques mencionados paraáluego abordar el problema desde una óptica que enfatice en la dinámica contradictoria de la sociedad romana

Conflicto político, demografía y modo de producción en la Antigua Roma, siglos II-I a.C

Este trabajo se propone analizar críticamente algunas teorías recientes sobre las consecuencias sociales de la Segunda Guerra Púnica (218-201 a. C.) en la antigua sociedadáromana. Mientras que laáinterpretación clásica había subrayado el efecto dañino que las guerras de expansión supusieronápara el campesinado romano, los nuevos enfoques en boga se caracterizan por dejar de lado las contradicciones del proceso histórico, adoptando una interpretación malthusiana en la cual laápoblación simplementeáhabría crecido mucho más que los recursos para sostenerla. Considerando que la demografía no es una variable independiente sino que se encuentra enmarcada en un modo de producción específico, se propone estudiar algunasálimitaciones de los enfoques mencionados paraáluego abordar el problema desde una óptica que enfatice en la dinámica contradictoria de la sociedad romana

Seawater carbonate chemistry and boron incorporation of planktic foraminifer Orbulina universa during experiments, 2011

Culture experiments with living planktic foraminifers reveal that the ratio of boron to calcium (B/Ca) in Orbulina universa increases from 56 to 92 µmol mol-1 when pH is raised from 7.61 +/- 0.02 to 8.67 +/- 0.03 (total scale). Across this pH range, the abundances of carbonate, bicarbonate, and borate ions also change (+ 530, - 500, and + 170 µmol kg-1, respectively). Thus specific carbonate system control(s) on B/Ca remain unclear, complicating interpretation of paleorecords. B/Ca in cultured O. universa also increases with salinity (55-72 µmol mol-1 from 29.9-35.4 per mil) and seawater boron concentration (62-899 µmol mol-1 from 4-40 ppm B), suggesting that these parameters may need to be taken into account for paleorecords spanning large salinity changes (~ 2 per mil) and for samples grown in seawater whose boron concentration ([B]SW) differs from modern by more than 0.25 ppm. While our results are consistent with the predominant incorporation of the charged borate species B(OH)4 into foraminiferal calcite, the behavior of the partition coefficient KD (defined as [B/Ca]calcite/B(OH)4/HCO3seawater) cannot be explained by borate incorporation alone, and suggests the involvement of other pH-sensitive ions such as CO3 For a given increase in seawater B(OH)4, the corresponding increase in B/Ca is stronger when B(OH)4 is raised by increasing [B]SW than when it is raised by increasing pH. These results suggest that B incorporation controls should be reconsidered. Additional insight is gained from laser-ablation ICP-MS profiles, which reveal variable B/Ca distributions within individual shells.

Seawater carbonate chemistry and physiological responses of three temperate coralline algae in a laboratory experiment

Coralline algae are major calcifiers of significant ecological importance in marine habitats but are among the most sensitive calcifying organisms to ocean acidification. The elevated pCO2 effects were examined in three coralline algal species living in contrasting habitats from intertidal to subtidal zones on the north-western coast of Brittany, France: (i) Corallina elongata, a branched alga found in tidal rock pools, (ii) Lithophyllum incrustans, a crustose coralline alga from the low intertidal zone, and (iii) Lithothamnion corallioides (maerl), a free-living form inhabiting the subtidal zone. Metabolic rates were assessed on specimens grown for one month at varying pCO2: 380 (current pCO2), 550, 750 and 1000 µatm (elevated pCO2). There was no pCO2 effect on gross production in C. elongata and L. incrustans but L. incrustans respiration strongly increased with elevated pCO2. L. corallioides gross production slightly increased at 1000 µatm, while respiration remained unaffected. Calcification rates decreased with pCO2 in L. incrustans (both in the light and dark) and L. corallioides (only in the light), while C. elongata calcification was unaffected. This was consistent with the lower skeletal mMg/Ca ratio of C. elongata (0.17) relative to the two other species (0.20). L. incrustans had a higher occurrence of bleaching that increased with increasing pCO2. pCO2 could indirectly impact this coralline species physiology making them more sensitive to other stresses such as diseases or pathogens. These results underlined that the physiological response of coralline algae to near-future ocean acidification is species-specific and that species experiencing naturally strong pH variations were not necessarily more resistant to elevated pCO2 than species from more stable environment.

Orbital control on carbonate-lignite cycles on sediment core KAP-107 in the Ptolemais Basin, northern Greece

Time control is essential for the reconstruction of geological processes. We use a combination of relative and absolute methods to establish the chronology and related paleoclimatic processes for Late Neogene lacustrine sediment from the Ptolemais Basin, northern Greece. We determined changes in magnetic polarity and correlated them to the global magnetic polarity time scale, which again is calibrated by radiometric methods, to provide a low-resolution age model for the Upper Miocene to Lower Pliocene (7 - 3 Ma). Sedimentary successions show rhythmic alterations of lignites, clays, and marls. Using photospetrometry we measured this variability at 1-cm resolution, and correlated the pattern to known changes in earth's orbital parameters, namely to eccentricity and precession. For 230-m long borehole KAP-107 from the Amynteon Sub-Basin we obtained a high-resolution age model that spans 2 myr from 5.1 to 3.1 Ma, with age control points at insolation maxima (20-kyr resolution). We recommend using photospectrometry as reliable tool to establish orbital-based chronologies and to reconstruct paleoclimate variability at high resolution.

The Islamic Crossed-Arch Domes in Cordoba: Geometry and Structural Analysis of the “Capilla de Villaviciosa”

Crossed-arch domes are a singular type of ribbed vaults. Their characteristic feature is that the ribs that form the vault are intertwined, forming polygons or stars, leaving an empty space in the centre. The earliest known vaults of this type are found in the Great Mosque of Córdoba, built ca. 960 a.C. The type spread through Spain, and the north of Africa in the 10th to the 16th Centuries, and was used by Guarini and Vittone in the 17th and 18th Centuries in Italy. However, it was used only in a few buildings. Though the literature about the structural behaviour of ribbed Gothic vaults is extensive, so far no structural analysis of crossed arch domes has been made. The purpose of this work is, first to show the way to attack such an analysis within the frame of Modern Limit Analysis of Masonry Structures (Heyman 1995), and then to apply the approach to study the stability of the dome of the Capilla de Villaviciosa. The work may give some clues to art and architectural historians to understand better the origin and development of Islamic dome architecture.