Miracle-dz/UniFAR-FTUs huggingface dataset:
The effects of high Mg2+-to-Ca2+ ratios on frequency potentiation in hippocampal slices of young and aged rats.

In some central systems, excitatory postsynaptic potential (EPSP) amplitude increases substantially during repetitive synaptic stimulation ("frequency potentiation"), as does the probability of spike generation. An apparently analogous phenomenon at the neuromuscular junction ("frequency facilitation") depends on residual Ca2+ in nerve terminals. However, the mechanisms of central frequency potentiation are not completely defined and it is therefore not clear whether the patterns of Ca2+-dependent synaptic plasticity are fully analogous in central and peripheral systems. In addition, an age-related deficit in hippocampal frequency potentiation has been previously described, and the degree of sensitivity of this deficit to Mg2+-to-Ca2+ balance could yield important insights into its nature. In these studies, we used the hippocampal slice preparation to examine the effects of varying Mg2+-to-Ca2+ ratios in the artificial cerebrospinal fluid (ACF) on frequency potentiation in aged and young rats. Extracellular and intracellular methods were used to assess the responses of hippocampal CA1 neurons during orthodromic stimulation of the monosynaptic Schaffer-commissural pathway. In experiment 1, frequency potentiation of the hippocampal population spike during 7-Hz stimulation was found to be significantly greater in an ACF with a high Mg2+-to-Ca2+ ratio (2.7) than in an ACF with a normal Mg2+-to-Ca2+ ratio (0.5), for both young and aged rat slices. Aged slices exhibited less frequency potentiation than young in both media. In experiment 2, the field EPSP and population spike were monitored concurrently, and the differences in Mg2+-to-Ca2+ ratio between the high Mg2+-to-Ca2+ ACF ratio (2.0) and normal Mg2+-to-Ca2+ ACF ratio (1.0) were reduced, to determine whether aged and young brains differed in sensitivity to smaller variations in Mg2+-to-Ca2+ balance. Under these conditions, the effects of high Mg2+-to-Ca2+ ratios on frequency potentiation (at 7 Hz) were found to be most pronounced in aged rat slices, particularly for potentiation of the spike. No effects were seen of age or Mg2+-to-Ca2+ ratios on presynaptic fiber volley amplitudes. Field EPSP (but not spike) amplitudes were reduced with aging, in an input-output (I/O) stimulation series at control frequency (0.2 Hz). However, the high Mg2+-to-Ca2+ ACF ratio of (2.0), which improved field EPSP frequency potentiation, did not decrease control field EPSP amplitudes in the I/O series. Therefore, the effects of high MG2+-to-Ca2+ ACF ratio on brain frequency potentiation seem to be mediated in part by mechanisms other than the classical reduction of release probability. (ABSTRACT TRUNCATED AT 400 WORDS)
Intravenous infusion of glucose and the vasodilator sodium nitroprusside in combination with local hyperthermia: effects on tumour pH and tumour response in the BT4An rat tumour model.

The influence of sodium nitroprusside (SNP) induced hypotension on the extra-cellular tumour pH during local hyperthermia (HT), and on the cytotoxic effect of HT, was studied in the BT4An tumour transplanted to the hind limb of BD IX rats. Experiments with intravenous infusion of glucose before the HT/SNP combination were also performed. Local waterbath HT was given at 44 degrees C. Sodium nitroprusside was administered as a continuous i.v. infusion to lower the mean arterial blood pressure to 60 mmHg. Glucose was given as an i.v. infusion at a dosage of 4.8 g/kg body weight in 60 min before HT. Extracellular tumour pH was measured by a needle type glass electrode. The tumour pH fell from 7.19 to 6.81, on average, after 60 min HT. Sodium nitroprusside induced hypotension during HT did not increase the pH fall after 1 h HT, but the pH 60 min after discontinuation of HT was lower in this group than in the HT alone group. Pretreatment with glucose before HT gave similar results as the HT/SNP combination. When glucose was given before HT/SNP a highly relevant decline in tumour pH during HT from 7.22 to 5.95 was observed. In a separate tumour response experiment adding SNP to HT was found to prolong the tumour growth time. Pre-treatment with glucose before the HT/SNP combination prolonged the tumour growth time slightly. The applicability of this treatment protocol in the clinical treatment of patients is discussed.
Risk perception and condom use among married or cohabiting couples in KwaZulu-Natal, South Africa.

CONTEXT Most HIV prevention efforts focus on premarital and extramarital sexual behavior, but in areas with high HIV prevalence the protective needs of married and cohabiting couples are just as great and often go unmet. Condom use by these couples is generally low, with resistance from men and cultural norms commonly cited as barriers to increased use. METHODS A household survey was conducted in an urban and a rural area in KwaZulu-Natal, South Africa, in 1999-2000. From this survey, matched partners in 238 marital or cohabiting relationships were independently interviewed about condom use and attitudes toward condoms, knowledge of AIDS/HIV risk and self-efficacy in preventing HIV infection. Logistic regression analysis was used to assess relationships between condom use and selected demographic and HIV prevention characteristics. RESULTS Although couples' knowledge of condoms and where to obtain them was very high, only 15% of men and 18% of women reported consistent or occasional use. The level of use was 8% and 11% among men and women, respectively, in rural, less educated couples, and 29% and 34% among men and women in urban, more educated couples. A majority of urban women had favorable attitudes toward condoms, and they also reported higher self-efficacy regarding HIV prevention than did rural women. A woman's perceived risk of HIV infection from her partner was the most powerful predictor of condom use (odds ratio, 4.0). CONCLUSIONS The common belief that men's resistance to condom use within stable relationships cannot be overcome may be exaggerated. HIV prevention programs should address the reproductive health needs of these couples.
Mode of pollen-tube growth in Pistils of Myrica rubra (Myricaceae): a comparison with related families.

BACKGROUND AND AIMS It is generally known that fertilization is delayed for more than a few weeks after pollination in Fagales. Recent studies showed that, during that period, pollen tubes grew in pistils in close association with the development of the ovule in a five-step process in Casuarina (Casuarinaceae) and a four-step process in Alnus (Betulaceae). The number of pollen tubes was reduced from many to one, a fact suggesting that delayed fertilization plays a role for gametophyte selection. Myrica (Myricaceae) also shows delayed fertilization for >2 weeks after pollination, but nothing is known of how pollen tubes grow in the pistil during that period. METHODS Pollen-tube growth and the development of the ovule in pistils was investigated by fluorescent and scanning electron microscopy and analysis of microtome sections of the pistils. KEY RESULTS Developmental study of the pollen-tube growth in the pistil of M. rubra showed that the tip of the pollen tube was branched or lay in a zigzag pattern in the upper space of the ovarian locule or near the tip of the integument, and subsequently was swollen on the nucellar surface. Such morphological changes indicate that the pollen-tube growth was temporarily arrested before fertilization. The pollen-tube growth in M. rubra can therefore be summarized as occurring in three steps: (1) from the stigma to the ovarian locule; (2) from the ovarian locule to the nucellar surface; and (3) from the nucellar surface to the embryo sac. CONCLUSION Myrica differs from other families in that the pollen tubes arrest their growth on the nucellar surface, probably digesting nutrient from nucellar cells. There is little information on five other families of Fagales. An extensive study is needed to better understand the diversity and function of the mode of pollen-tube growth within the order.
Mountain Pine Beetle Develops an Unprecedented Summer Generation in Response to Climate Warming

The mountain pine beetle (MPB; Dendroctonus ponderosae) is native to western North America, attacks most trees of the genus Pinus, and periodically erupts in epidemics. The current epidemic of the MPB is an order of magnitude larger than any previously recorded, reaching trees at higher elevation and latitude than ever before. Here we show that after 2 decades of air-temperature increases in the Colorado Front Range, the MPB flight season begins more than 1 month earlier than and is approximately twice as long as the historically reported season. We also report, for the first time, that the life cycle in some broods has increased from one to two generations per year. Because MPBs do not diapause and their development is controlled by temperature, they are responding to climate change through faster development. The expansion of the MPB into previously inhospitable environments, combined with the measured ability to increase reproductive output in such locations, indicates that the MPB is tracking climate change, exacerbating the current epidemic.
Electrophysiology of the facial nerve in hemifacial spasm: Ectopic/ephaptic excitation

Pathologic and pathophysiologic findings in hemifacial spasm are reviewed in connection with recent theoretical and experimental studies of ectopic/ephaptic excitation. The intracranial segment of the normal facial nerve is ensheathed by an arachnoid membrane only and shows no fascicular organization. In hemifacial spasm, this segment shows signs of demyelination. Several electrical phenomena relating to ectopic excitation, ephaptic transmission between facial nerve fibers, and autoexcitation can be reproduced in clinical electrophysiologic studies of hemifacial spasm. These abnormalities gradually disappear after facial nerve decompression in the cerebellopontine recess. It is concluded that (1) the normal facial nerve is vulnerable to minor compression, (2) the primary pathophysiologic mechanism in hemifacial spasm is ectopic/ephaptic excitation due to compression and demyelination of the intracranial segment of the facial nerve, and (3) the facial nerve in hemifacial spasm is a useful model for the study of ephaptic transmission, which has provided new information about the resolution of abnormal electrical events after decompression.
A simple electronic alert for acute kidney injury

Background: Acute kidney injury (AKI) is frequently under-recognized and contributes to poor outcomes. Electronic alerts (e-alerts) to highlight AKI based on changes in serum creatinine may facilitate earlier recognition and treatment, and sophisticated algorithms for AKI detection have been proposed or implemented elsewhere. However, many laboratories currently lack the resources or capability to replicate these systems. Methods: A real-time automated delta check e-alert flags a 50% increase in creatinine to a concentration of >50 µmol/L from the most recent result within a 90-day period and automatically adds the comment ‘? AKI – creatinine increase >50% from previous’ with a link to local AKI guidelines. In addition, creatinine results >300 µmol/L are retrospectively reviewed and phoned if AKI is suspected. For each alert over a 12-day period we manually reviewed previous and subsequent creatinine results to determine baseline creatinine and stage AKI according to Acute Kidney Injury Network (AKIN) criteria. Results: From 11,930 creatinine requests, 63 of 90 (70%) delta check e-alerts were due to AKI, identifying 61 episodes of AKI. Thirty four of 54 (63%) creatinine results >300 µmol/L were due to AKI, identifying a further 10 episodes of AKI. The positive predictive value (PPV) for AKI of a delta check e-alert was greater when the trigger creatinine was >100 µmol/L (PPV 89%) or when the absolute change in creatinine was >50 µmol/L (PPV 93%). Conclusion: This study demonstrates that a simple automated delta check can detect and flag AKI in real time, continuously, at little extra cost and without manual input.
Impressive predictive value of ankle-brachial index for very long-term outcomes in patients with cardiovascular disease: IMPACT-ABI study

Background The ankle—brachial index (ABI) is a marker of generalized atherosclerosis and is predictive of future cardiovascular events. However, few studies have assessed its relation to long-term future cardiovascular events, especially in patients with borderline ABI. We therefore evaluated the relationship between long-term future cardiovascular events and ABI. Methods In the IMPACT-ABI study, a single-center, retrospective cohort study, we enrolled 3131 consecutive patients (67 ± 13 years; 82% male) hospitalized for cardiovascular disease and measured ABI between January 2005 and December 2012. After excluding patients with an ABI > 1.4, the remaining 3056 patients were categorized as having low ABI (≤ 0.9), borderline ABI (0.91–0.99), or normal ABI (1.00–1.40). The primary endpoint was MACE (cardiovascular death, myocardial infarction [MI] and stroke). The secondary endpoints were cardiovascular death, MI, stroke, admission due to heart failure, and major bleeding. Results During a 4.8-year mean follow-up period, the incidences of MACE (low vs. borderline vs. normal: 32.9% vs. 25.0% vs. 14.6%, P<0.0001) and cardiovascular death (26.2% vs. 18.7% vs. 8.9%, P<0.0001) differed significantly across ABIs. The incidences of stroke (9.1% vs. 8.6% vs. 4.8%, P<0.0001) and heart failure (25.7% vs. 20.8% vs. 8.9%, P<0.0001) were significantly higher in the low and borderline ABI groups than in the normal ABI group. But the incidences of MI and major bleeding were similar in the borderline and normal ABI groups. The hazard ratios for MACE adjusted for traditional atherosclerosis risk factors were significantly higher in patients with low and borderline ABI than those with normal ABI (HR, 1.93; 95%CI: 1.44–2.59, P < 0.0001, HR, 1.54; 95% CI: 1.03–2.29, P = 0.035). Conclusions The incidence of long-term adverse events was markedly higher among patients with low or borderline ABI than among those with normal ABI. This suggests that more attention should be paid to patients with borderline ABIs, especially with regard to cardiovascular death, stroke, and heart failure.
The Role of a Manager’s Intangible Capabilities in Resource Acquisition and Sustainable Competitive Performance

The answer to the challenging question, “Should one either invest in tangible resources or intangible resources/capabilities? ” is still fragmented. In prior studies, more emphasis is given to tangible resources, while intangible resources have comparatively received minor attention, despite their significant role in the success of small and medium enterprises (SMEs). Particularly the role of the intangible skills; intellectual capital, financial literacy (FL), and business experience (BE) in resource acquisition and sustainable competitive performance has missed in prior studies. Grounded on the resource-based view and upper echelon theory, this study examines the role of intellectual capital in sustainable competitive performance with a mediating role of resource acquisition. This research also assesses the moderating role of financial literacy and business experience between intellectual capital and resource acquisition. Data are collected through structured questionnaires from 384 owners/managers of Pakistani SMEs. After analyzing the data through structural equation modeling (SEM), the results indicate that intellectual capital helps managers in acquiring valuable resources, which in turn enhance sustainable competitive performance. Resource acquisition partially mediates the relation between intellectual capital and sustainable competitive performance. Financial literacy is a significant predictor of resource acquisition, but it does not significantly moderate the relation between intellectual capital and sustainable competitive performance. Business experience significantly boosts the acquisition of resources and strengthens the path between intellectual capital and resource acquisition. SMEs should encourage their managers to acquire unique, rare, and immutable external resources in the turbulent markets.
Undernutrition affects embryo quality of superovulated ewes

Summary To determine the effect of undernutrition on embryo production and quality in superovulated sheep, 45 ewes were allocated into two groups to be fed diets that provided 1.5 (control, C; n = 20) or 0.5 (low nutrition, L; n = 25) times daily requirements for maintenance, from oestrous synchronization with intravaginal sponges to embryo collection. Embryos were collected 7 days after the onset of oestrus (day 0). Low nutrition resulted in lower live weight and body condition at embryo collection (P < 0.05). Diet (P < 0.01) and day of sampling (P < 0.001) significantly affected plasma non-esterified fatty acid (NEFA) and insulin concentrations. Plasma leptin concentrations decreased on day 7 only in L ewes. A significant effect of dietary treatment (P < 0.05) and day (P < 0.0001) was observed on plasma insulin-like growth factor (IGF)-I concentrations. The number of recovered oocytes and embryos did not differ between the groups (L: 15.4 ± 0.4; C: 12.4 ± 0.4). Recovery rate was lower (P < 0.05) in the L (60%) than in the C group (73%). The total number of embryos and number of viable-transferable embryos (5.0 ± 0.3 and 3.4 ± 0.3 embryos, respectively) of the L group were lower (P < 0.1) when compared with controls (8.4 ± 0.4 and 6.2 ± 0.4 embryos, respectively). Undernutrition during the period of superovulation and early embryonic development reduced total and viable number of embryos. These effects might be mediated by disruption of endocrine homeostasis, oviduct environment and/or oocyte quality.
Proliferation of myogenic stem cells in human skeletal muscle in response to low‐load resistance training with blood flow restriction

In the last decade muscle training performed using a combination of low external loads and partial restriction of blood flow to the exercising limb has gained increasing interest, since it leads to significant gains in muscle strength and muscle mass. The cellular mechanisms responsible for the muscular adaptations induced by this training paradigm are not fully understood. This study shows that 3 weeks of high‐frequency, low‐intensity muscle exercise with partial blood flow restriction induces increases in maximal muscle strength accompanied by highly marked gains in muscle fibre size. Furthermore, the results indicate that these muscular adaptations rely on a considerable upregulation in myogenic satellite cells number, resulting in nuclear addition to the exercised myofibres. The results contribute to a better understanding of the physiological mechanisms underlying the gain in muscle strength and muscle mass observed with blood flow restricted low‐intensity resistance exercise.
Influence of repeated restraint and isolation stress and electrolyte administration on pituitary-adrenal secretions, electrolytes, and other blood constituents of sheep.

Crossbred lambs (n = 24) were blocked by weight and assigned within blocks to four treatments applied in two replications of a 2 x 2 factorial arrangement. Main effects included no stress (NS) or three consecutive days of restraint and isolation stress (RIS) and treatment with either water (W) or an electrolyte (E) solution. Each lamb in the RIS treatment group was moved from its home stanchion to another room, isolated from visual and tactile contact with other lambs, and restrained for 6 h on three consecutive days. Lambs received either distilled W or E (320 mL) on each of the 3 d of stressor treatment. On the morning of the 3rd d of stressor treatment, blood samples were collected at 1-h intervals for 6 h for determination of concentrations of ACTH, cortisol, and lactate. Also, blood was collected at the conclusion of, and 18 h after, the termination of stressor treatment (at slaughter) to measure serum electrolyte concentrations and other blood constituents. Polynomial curves fit to plasma concentrations of ACTH, cortisol, and lactate data differed (P < .005) between RIS and NS lambs during the last 6-h stressor bout. Stressed lambs had lower (P < .05) serum calcium and alkaline phosphatase concentrations than did NS lambs. Serum glutamic oxaloacetic transaminase was increased (P < .05) 20- to 30-fold in RIS lambs. Restraint and isolation stress caused clear increases in plasma concentrations of ACTH, cortisol, lactate, and glutamic oxaloacetic transaminase but had minimal effects on serum electrolytes. Electrolyte treatment had no appreciable effect on pituitary-adrenal secretions or any other measured component of blood.
Relative Expression Levels of the HLA Class-I Proteins in Normal and HIV-Infected Cells

The expression level of HLA class-I proteins is known to influence pathological outcomes: pathogens downregulate HLA to evade host immune responses, host inflammatory reactions upregulate HLA, and differences among people with regard to the steady-state expression levels of HLA associate with disease susceptibility. Yet precise quantification of relative expression levels of the various HLA loci is difficult because of the tremendous polymorphism of HLA. We report relative expression levels of HLA-A, HLA-B, HLA-C, and HLA-E proteins for the specific haplotype A*02:01, B*44:02, C*05:01, which were characterized using two independent methods based on flow cytometry and mass spectrometry. PBLs from normal donors showed that HLA-A and HLA-B proteins are expressed at similar levels, which are 13–18 times higher than HLA-C by flow cytometry and 4–5 times higher than HLA-C by mass spectrometry; these differences may reflect variation in the conformation or location of proteins detected. HLA-E was detected at a level 25 times lower than that of HLA-C by mass spectrometry. Primary CD4+ T cells infected with HIV in vitro were also studied because HIV downregulates selective HLA types. HLA-A and HLA-B were reduced on HIV-infected cells by a magnitude that varied between cells in an infected culture. Averaging all infected cells from an individual showed HLA-A to be 1–3 times higher and HLA-B to be 2–5 times higher than HLA-C by flow cytometry. These results quantify substantial differences in expression levels of the proteins from different HLA loci, which are very likely physiologically significant on both uninfected and HIV-infected cells.
A robust SDN network architecture for service providers

Large scale networks, such as those deployed by Service Providers (SPs), employ robust architectures, capable of supporting large volumes of traffic with very different characteristics. Their network equipment has significant processing load, being responsible for building both a routing logic and the routing of traffic itself. By having the network control implemented in a distributed manner and being built with a limited number of vendors, these networks have limitations of control and traffic engineering, hindering the differentiation among SPs. Additionally, the network intelligence is hidden in the network equipment, making innovations very slow and conditioned to the vendors interests. As an alternative option, this work proposes a Software Defined Networking (SDN)-OpenFlow network architecture that attempts to improve the previously mentioned problems, and, at the same time, to solve the arising difficulties related to the SDN network centralized feature. With the proposed architecture, a robust SP SDN-OpenFlow network is created to support high controller response times and controller outages, without additional delays in the creation of flows and with significant reduction of the controller load. A prototype has been built using Open vSwitch as a virtualization software for OpenFlow clients, Mininet for the topology construction and Ryu as the controller, all with OpenFlow 1.3 support. The obtained results are general and can be extended to other types of networks.