Chlorophyll fluorescence data reveals climate-related photosynthesis seasonality in Amazonian forests

This is the final version of the article. Available from MDPI via the DOI in this record.Amazonia is theworld largest tropical forest, playing a key role in the global carbon cycle. Thus, understanding climate controls of photosynthetic activity in this region is critical. The establishment of the relationship between photosynthetic activity and climate has been controversial when based on conventional remote sensing-derived indices. Here, we use nine years of solar-induced chlorophyll fluorescence (ChlF) data from the Global Ozone Monitoring Experiment (GOME-2) sensor, as a direct proxy for photosynthesis, to assess the seasonal response of photosynthetic activity to solar radiation and precipitation in Amazonia. Our results suggest that 76% of photosynthesis seasonality in Amazonia is explained by seasonal variations of solar radiation. However, 13% of these forests are limited by precipitation. The combination of both radiation and precipitation drives photosynthesis in the remaining 11% of the area. Photosynthesis tends to rise only after radiation increases in 61% of the forests. Furthermore, photosynthesis peaks in the wet season in about 58% of the Amazon forest. We found that a threshold of ≈1943 mm per year can be defined as a limit for precipitation phenological dependence. With the potential increase in the frequency and intensity of extreme droughts, forests that have the photosynthetic process currently associated with radiation seasonality may shift towards a more water-limited system.We gratefully acknowledge the CAPES and FAPESP (Grants No. 13/14520-6 and No. 2013/50533-5) agencies for providing research fellowships and support this work. L.O.A and L.E.O.C.A thank the National Council for Scientific and Technological Development (CNPq), for the productivity fellowship, processes number 309247/2016-0 and 305054/2016-3, respectively. F.H.W. have been funded by the FAPESP (process number 13/14520-6, process number 15/50484-0 and process number 16/17652-9)

The femoral insertions of the anteromedial and posterolateral bundles of the anterior cruciate ligament: a radiographic evaluation

The aim of this radiographic study was to visualize the femoral insertion sites of the anteromedial (AM) and posterolateral (PL) bundle of the anterior cruciate ligament (ACL) on lateral radiographs in different angles of knee flexion to gain better understanding for arthroscopic femoral tunnel placement in ACL double bundle reconstruction. Four fresh cadaveric knees with an intact ACL were dissected to isolate the AM and PL bundle of the ACL. We obtained lateral radiographs of each knee over the range of 0°–90° flexion in 30° increments after painting the bundles with a radiopaque tantalum powder. The center of the radiographically marked femoral insertion was defined for each bundle on the lateral roentgenogram. We analyzed the relationship of knee flexion and the projection of the relative position of the femoral insertion sites of both bundles of the ACL on the lateral roentgenogram. The centre of the PL bundle visualized more anterior and distal than the centre of the AM bundle with the knee held in 90° flexion. The centers of the AM and PL bundle were horizontally aligned when the knee was flexed over 90°. The resulting images allow a radiographic description of the femoral insertion sites of both bundles in different angles of knee flexion. It is essential to be aware of the degree of knee flexion when drilling the femoral tunnels

Determinants of Left Ventricular Functional Recovery After Thrombolytic Therapy and/or Immediate Coronary Angioplasty in Acute Myocardial Infarction

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74934/1/j.1540-8183.1988.tb00403.x.pd

A combination of l-arabinose and chromium lowers circulating glucose and insulin levels after an acute oral sucrose challenge

<p>Abstract</p> <p>Background</p> <p>A growing body of research suggests that elevated circulating levels of glucose and insulin accelerate risk factors for a wide range of disorders. Low-risk interventions that could suppress glucose without raising insulin levels could offer significant long-term health benefits.</p> <p>Methods</p> <p>To address this issue, we conducted two sequential studies, the first with two phases. In the first phase of Study 1, baseline fasting blood glucose was measured in 20 subjects who consumed 70 grams of sucrose in water and subsequently completed capillary glucose measurements at 30, 45, 60 and 90 minutes (Control). On day-2 the same procedure was followed, but with subjects simultaneously consuming a novel formula containing l-arabinose and a trivalent patented food source of chromium (LA-Cr) (Treatment). The presence or absence of the LA-Cr was blinded to the subjects and testing technician. Comparisons of changes from baseline were made between Control and Treatment periods. In the second phase of Study 1, 10 subjects selected from the original 20 competed baseline measures of body composition (DXA), a 43-blood chemistry panel and a Quality of Life Inventory. These subjects subsequently took LA-Cr daily for 4 weeks completing daily tracking forms and repeating the baseline capillary tests at the end of each of the four weeks. In Study 2, the same procedures used in the first phase were repeated for 50 subjects, but with added circulating insulin measurements at 30 and 60 minutes from baseline.</p> <p>Results</p> <p>In both studies, as compared to Control, the Treatment group had significantly lower glucose responses for all four testing times (AUC = <it>P </it>< 0.0001). Additionally, the Treatment was significantly more effective in lowering circulating insulin after 60 minutes from baseline (AUC = <it>P </it>= < 0.01). No adverse effects were found after acute sucrose challenge or in those who consumed LA-Cr daily for four weeks.</p> <p>Conclusions</p> <p>As compared to a placebo control, consumption of a LA-Cr formula after a 70-gram sucrose challenge was effective in safely lowering both circulating glucose and insulin levels.</p> <p>Trial Registration</p> <p>Clinical Trials.gov, <a href="http://www.clinicaltrials.gov/ct2/show/NCT0110743">NCT0110743</a></p

Dermatitis associated with exposure to a marine cyanobacterium during recreational water exposure

<p>Abstract</p> <p>Background</p> <p>Anecdotal evidence reported an outbreak of symptoms on Fraser Island during the late 1990s similar to those expected from exposure to dermotoxins found in the cyanobacterium <it>L. majuscula</it>. This coincided with the presence of a bloom of <it>L. majuscula</it>.</p> <p>Methods</p> <p>Records from the Fraser Island National Parks First aid station were examined. Information on cyanobacterial blooms at Fraser Island were obtained from Queensland National Parks rangers.</p> <p>Results</p> <p>Examination of first aid records from Fraser Island revealed an outbreak of symptoms predominantly in January and February 1998.</p> <p>Conclusion</p> <p>During a bloom of <it>L. majuscula </it>there were numerous reports of symptoms that could be attributed to dermotoxins found in <it>L. majuscula</it>. The other four years examined had no <it>L. majuscula </it>blooms and the number of <it>L. majuscula </it>symptoms was much reduced. These cases comprised a high percentage of the cases treated at the first aid station.</p

DNA topoisomerases participate in fragility of the oncogene RET

Fragile site breakage was previously shown to result in rearrangement of the RET oncogene, resembling the rearrangements found in thyroid cancer. Common fragile sites are specific regions of the genome with a high susceptibility to DNA breakage under conditions that partially inhibit DNA replication, and often coincide with genes deleted, amplified, or rearranged in cancer. While a substantial amount of work has been performed investigating DNA repair and cell cycle checkpoint proteins vital for maintaining stability at fragile sites, little is known about the initial events leading to DNA breakage at these sites. The purpose of this study was to investigate these initial events through the detection of aphidicolin (APH)-induced DNA breakage within the RET oncogene, in which 144 APHinduced DNA breakpoints were mapped on the nucleotide level in human thyroid cells within intron 11 of RET, the breakpoint cluster region found in patients. These breakpoints were located at or near DNA topoisomerase I and/or II predicted cleavage sites, as well as at DNA secondary structural features recognized and preferentially cleaved by DNA topoisomerases I and II. Co-treatment of thyroid cells with APH and the topoisomerase catalytic inhibitors, betulinic acid and merbarone, significantly decreased APH-induced fragile site breakage within RET intron 11 and within the common fragile site FRA3B. These data demonstrate that DNA topoisomerases I and II are involved in initiating APH-induced common fragile site breakage at RET, and may engage the recognition of DNA secondary structures formed during perturbed DNA replication

Phenotypic Variation and Bistable Switching in Bacteria

Microbial research generally focuses on clonal populations. However, bacterial cells with identical genotypes frequently display different phenotypes under identical conditions. This microbial cell individuality is receiving increasing attention in the literature because of its impact on cellular differentiation, survival under selective conditions, and the interaction of pathogens with their hosts. It is becoming clear that stochasticity in gene expression in conjunction with the architecture of the gene network that underlies the cellular processes can generate phenotypic variation. An important regulatory mechanism is the so-called positive feedback, in which a system reinforces its own response, for instance by stimulating the production of an activator. Bistability is an interesting and relevant phenomenon, in which two distinct subpopulations of cells showing discrete levels of gene expression coexist in a single culture. In this chapter, we address techniques and approaches used to establish phenotypic variation, and relate three well-characterized examples of bistability to the molecular mechanisms that govern these processes, with a focus on positive feedback.

Measurements of the transverse-momentum-dependent cross sections of J /ψ production at mid-rapidity in proton+proton collisions at s =510 and 500 GeV with the STAR detector

We present measurements of the differential cross sections of inclusive J/ψ meson production as a function of transverse momentum (pTJ/ψ) using the μ+μ- and e+e- decay channels in proton+proton collisions at center-of-mass energies of 510 and 500 GeV, respectively, recorded by the STAR detector at the Relativistic Heavy Ion Collider. The measurement from the μ+μ- channel is for