Increasing sensitivity of coal analysis by gamma-albedo method.

The article deals with the methodological features of the gamma-albedo method and ways to increase sensitivity of measuring the coal ash content. On the basis of the developed mathematical model the inverse nature of sensitivity of the method is studied depending on the energy of primary gamma radiation. The need for a differentiated account of the nature of scattering that allows using a selective filter as a means of increasing sensitivity is revealed. It is shown that the qualitatively different nature of changing the mass coefficients of coherent and incoherent scattering of gamma radiation from its energy and effective atomic number allows increasing sensitivity of ash measurement according to the value of the ratio of coherently and incoherently scattered gamma radiation intensities. There is given the comparison of the sensitivity data for various modifications of the gamma-albedo method.

Express measurement of solid fuel ash content by nuclear gamma-method.

The methodological features of determining the ash content in coal using scattered gamma radiation are considered in the present study. Theoretical and experimental studies have shown that the integral intensity of secondary (scattered and fluorescent) radiation can serve as an instrumental signal depending on the quality of coal. To achieve a more unambiguous relationship between the integral radiation intensity and the ash content in coal of variable material composition, a compensation technique has been proposed consisting in artificial attenuating secondary radiation. The laws governing the integral intensity of radiation depending on the inverse thickness of the filter are studied, and the results are found to be invariant with variations in the ash composition. A model has been developed to optimize the filtering parameters of secondary radiation by considering the regularity of changes in the filter inversion thickness depending on the ash content.

Asymmetric interactions and their consequences for vital rates and dynamics: the smaller tea tortrix as a model system.

Asymmetric interactions among conspecifics can have diverse effects on population dynamics including stabilization, generation of cycles, and induction of chaotic fluctuations. A difficult challenge, however, is establishing the link between the impact of asymmetric interactions on life history and the consequences for population dynamics. The smaller tea tortrix, Adoxophyes honmai, is a good example. Larval instars differ dramatically in size and have a tendency for cannibalism, which suggests the potential for strong asymmetric interactions among instars. Yet whether these asymmetries have any role in generating the distinct single-generation cycles observed in the field and laboratory is unclear. Here we report on the development of a new experimental approach to characterize the impact of asymmetric interactions on life history that can be directly embedded into stage-structured population models. The experiments use donor-replacement protocols in which focal individuals are challenged to complete their life cycles in competitive environments where the instar and density of the competitors are held constant. The experimentally derived interaction surface contains all the information about stage-specific interactions and provides a straightforward framework for evaluating alternative ways of abstracting the interactions into traditional models of asymmetric competition. Working with the smaller tea tortrix, we found strong evidence of asymmetric interactions and identified critical "tipping points" in the competitive environment that strongly affected survival but not development. We incorporated the experimentally derived interaction surface into a stage-structured population model and found that despite the strong impact that asymmetric interactions have on tea tortrix life history, they do not scale-up to impact the predicted asymptotic population dynamics. Comparing these dynamics with two abstracted models of stage-structured interactions revealed that while the quantitative details of the emergent dynamics depends on the shape of the interaction surface, the qualitative features, such as the emergence of single-generation cycles and rapid synchronization of development among individuals, are pleasingly robust.

Mapping homeostatic synaptic plasticity using cable properties of dendrites.

When chronically silenced, cortical and hippocampal neurons homeostatically upregulate excitatory synaptic function. However, the subcellular position of such changes on the dendritic tree is not clear. We exploited the cable-filtering properties of dendrites to derive a parameter, the dendritic filtering index (DFI), to map the spatial distribution of synaptic currents. Our analysis indicates that young rat cortical neurons globally scale AMPA receptor-mediated currents, while mature hippocampal neurons do not, revealing distinct homeostatic strategies between brain regions and developmental stages. The DFI presents a useful tool for mapping the dendritic origin of synaptic currents and the location of synaptic plasticity changes.

[The choice of reconstructive operation in the treatment of patients with breast cancer].

170 patients, operated on the reason of breast cancer, received reconstructive surgery. Of them 63 had simultaneous organ preserving surgery with extramammary tissues translocation; 52 had organ preserving operation with the use of reductional mammoplasty and 55 patients had subcutaneous mastectomy with nipple preservation. Results of the study demonstrate that the method of organ preserving surgery with extramammary tissues translocation has more possibilities. The second place is occupied by the method of subcutaneous mastectomy with nipple preservation or in combination with muscular thoracodorsal flap replantation. The most complicated and giving the worst cosmetic result is the use of TRAM plasty. The algorithm of choice of the reconstructive operation for patients with breast cancer was worked out. Long term follow up showed the tumor progression in 29 (17.1%), remote metastases in 15 (8.8%) and local recurrence in 6 (3.5%) patients after organpreserving surgery and in 2 (1.2%) patients after subcutaneous mastectomy.

Aging in the cerebellum and hippocampus and associated behaviors over the adult life span of CB6F1 mice.

In the present study we examined the effects of normal aging in the hippocampus and cerebellum, as well as behaviors associated with these substrates. A total of 67 CB6F1 hybrid mice were tested at one of five ages (4, 8, 12, 18 or 25 months) on the context pre-exposure facilitation effect (CPFE) modification of fear conditioning, rotorod, Barnes maze, acoustic startle, Morris water maze (MWM) and 500-ms trace eyeblink classical conditioning (EBCC). Behavioral tasks were chosen to increase the ability to detect age-related changes in learning, as trace EBCC is considered a more difficult paradigm (compared to delay EBCC) and the CPFE has been found to be more sensitive to hippocampus insults than standard contextual fear conditioning. To assess the effects of age on the brain, hippocampus volume was calculated and unbiased stereology was used to estimate the number of Purkinje neurons in the cerebellar cortex. A significant, age-related loss of Purkinje neurons was found-beginning at 12 months of age-and hippocampus volume remained stable over the adult life span. Age-related impairment was found, beginning at 12-18 months in the rotorod, and mice with fewer Purkinje neurons showed greater impairment in this task. CB6F1 mice retained auditory acuity across the life span and mice aged 25 months showed significant age-related impairment in the EBCC task; however, deficits were not associated with the loss of Purkinje neurons. Although the CPFE task is considered more sensitive to hippocampus insult, no age-related impairment was found. Spatial memory retention was impaired in the Barnes maze at 25 months, but no significant deficits were seen in the MWM. These results support the finding of differential aging in the hippocampus and cerebellum.

Effectiveness of proprioceptive exercises for ankle ligament injury in adults: a systematic literature and meta-analysis.

The purpose of this study was to assess the effectiveness of such proprioceptive exercise following ankle ligament injury. A systematic review of the databases MEDLINE, EMBASE, CINHAL, AMED, the Cochrane library database and the PEDro database, in addition to unpublished literature databases was conducted to July 2011. When appropriate, meta-analysis was conducted to pool results from homogeneous studies. The methodological quality of the literature was reviewed using the Critical Appraisal Skills Programme tool. The results indicated that there is no statistically significant difference in recurrent injury between the addition of proprioceptive exercises during the rehabilitation of patients following ankle ligament injury (p = 0.68). The addition of proprioceptive training demonstrated a significant reduction in subjective instability and functional outcomes (p < 0.05). There was no consensus on the advantages of including proprioceptive training in the rehabilitation of this population for swelling, postural sway, joint position sense, ankle range of motion or return to sport outcomes. Further study is warranted to develop the rigour of the evidence-base and to determine the optimal proprioceptive training programme following ankle ligament injury with different populations.

Identification and functional characterization of polo-like kinase 2 autoregulatory sites.

Polo family kinases play important roles in cellular proliferation as well as neuronal synaptic plasticity. However, the posttranslational regulation of these kinases is not fully understood. Here, we identified several novel Plk2 phosphorylation sites stimulated by Plk2 itself. By site-directed mutagenesis, we uncovered three additional hyperactivating Plk2 mutations as well as a series of residues regulating Plk2 steady-state expression level. Because of the established role of Plk2 in homeostatic negative control of excitatory synaptic strength, these phosphorylation sites could play an important role in the rapid activation, expansion, and prolongation of Plk2 signaling in this process.

[Results of single-stage reconstructive surgery in breast cancer patients (a report of 1143 cases)].

Our experience with 1143 single-stage surgeries in breast cancer patients undergoing skin-sparing mastectomies and breast-conserving surgery is presented. Both patients' tissues and silicone implants were used for reconstruction purposes. Latissimus dorsi muscle in combination with endoprothesis was used in 592 patients. The lowest local recurrence rate was reported in the skin-sparing mastectomy group, obviously due to a greater amount of tissues dissected.

Beta amyloid-independent role of amyloid precursor protein in generation and maintenance of dendritic spines.

Synapse loss induced by amyloid beta (Abeta) is thought to be a primary contributor to cognitive decline in Alzheimer's disease. Abeta is generated by proteolysis of amyloid precursor protein (APP), a synaptic receptor whose physiological function remains unclear. In the present study, we investigated the role of APP in dendritic spine formation, which is known to be important for learning and memory. We found that overexpression of APP increased spine number, whereas knockdown of APP reduced spine density in cultured hippocampal neurons. This spine-promoting effect of APP required both the extracellular and intracellular domains of APP, and was accompanied by specific upregulation of the GluR2, but not the GluR1, subunit of AMPA receptors. In an in vivo experiment, we found that cortical layers II/III and hippocampal CA1 pyramidal neurons in 1 year-old APP-deficient mice had fewer and shorter dendritic spines than wild-type littermates. In contrast, transgenic mice overexpressing mutant APP exhibited increased spine density compared to control animals, though only at a young age prior to overaccumulation of soluble amyloid. Additionally, increased glutamate synthesis was observed in young APP transgenic brains, whereas glutamate levels were decreased and GABA levels were increased in APP-deficient mice. These results demonstrate that APP is important for promoting spine formation and is required for proper spine development.

Hippocampal spine-associated Rap-specific GTPase-activating protein induces enhancement of learning and memory in postnatally hypoxia-exposed mice.

Spine-associated Rap-specific GTPase-activating protein (SPAR) is a postsynaptic protein that forms a complex with postsynaptic density (PSD)-95 and N-methyl-d-aspartate receptors (NMDARs), and morphologically regulates dendritic spines. Mild intermittent hypoxia (IH, 16.0% O(2), 4 h/day for 4 weeks) is known to markedly enhance spatial learning and memory in postnatal developing mice. Here, we report that this effect is correlated with persistent increases in SPAR expression as well as long-term potentiation (LTP) in the hippocampus of IH-exposed mice. Furthermore, an infusion of SPAR antisense oligonucleotides into the dorsal hippocampus disrupted elevation of SPAR expression, preventing enhanced hippocampal LTP in IH-exposed developing mice and also reducing LTP in normoxic mice, without altering basal synaptic transmission. In SPAR antisense-treated mice, acquisition of the Morris water maze spatial learning task was impaired, as was memory retention in probe trails following training. This study provides the first evidence that SPAR is functionally required for synaptic plasticity and contributes to the IH-induced enhancement of spatial learning and memory in postnatal developing mice.

[Axillar-subclavian-subscapular area plasty after radical mastectomy for breast cancer].

Indexes of lymphorrhea and rates of early and late complications of the radical mastectomy were studied in 153 patients with breast cancer. Axillar-subclavian-subscapular area plasty with latissimus dorsi muscle fragment is worked out and applied to prevent complications after mastectomy. The use of the method allowed reducing the volume and duration of postoperative lymphorrhea on 45.5% and to 7 days, respectively, after Madden procedure, on 46.8% and to 11 days, respectively, after modified radical mastectomies. It also allowed reducing the wound healing complication rates from 21.8 to 5.4% after Madden procedure and from 58.1 to 16.7% after modified radical mastectomies; rates of postmastectomy oedema of I-II stage from 48 to 18.5%, rates of pain syndrome from 32.7 to 7.4%.

Stereological estimation of Purkinje neuron number in C57BL/6 mice and its relation to associative learning.

Cerebellar Purkinje neurons are among the most vulnerable neurons in the CNS. Impairment in Purkinje neurons has consequences for cerebellar cortical-dependent forms of behavior. The primary aim of this study was to evaluate Purkinje neuron number over the lifespan of C57BL/6 mice. Stereological estimates of the total number of Purkinje neurons in cerebellar cortex were made in 25 C57BL/6 mice aged 4, 8, 12, 18, and 24 months. Delay eyeblink classical conditioning to a white noise conditioned stimulus was also assessed for 10 daily sessions. Statistically significant age differences in Purkinje neuron number were observed beginning at 18 months. Delay eyeblink conditioning also showed significant age-related impairment, at least some of which resulted from age-related deficits in hearing. Eliminating the hearing-impaired 18- and 24-month-old mice from the analysis, the correlation between Purkinje neuron number and rate of conditioning was -0.435 (P=0.053) in 15 younger mice aged 4-12 months. Purkinje neurons are one of the few types of neurons showing significant age-associated loss. Results indicate that individual variation in Purkinje neuron number is related to eyeblink conditioning in young organisms suggesting that reserves of neuron numbers against which individuals draw are defined early in life.

Mecamylamine interactions with galantamine and donepezil: effects on learning, acetylcholinesterase, and nicotinic acetylcholine receptors.

Patch-clamp recordings of single ion channel activity demonstrated that donepezil, but not galantamine, could be blocked by the nicotinic cholinergic antagonist mecamylamine, suggesting that galantamine acted at a separate (allosteric) site. The aim of this experiment was to demonstrate at a whole organism, behavioral level that galantamine, but not donepezil, could reverse mecamylamine-induced learning impairment. Forty-four young female rabbits received 15 sessions in the 750-ms delay eyeblink classical conditioning procedure, after one of five drug treatments: 0.5 mg/kg mecamylamine, 3.0 mg/kg donepezil, 0.5 mg/kg mecamylamine plus 3.0 mg/kg galantamine, 0.5 mg/kg mecamylamine plus 3.0 mg/kg donepezil, or sterile saline vehicle. An additional 24 young female rabbits were tested in the explicitly unpaired condition after treatment with the same mecamylamine plus galantamine or donepezil combinations or with vehicle. In a previous study we demonstrated that 3.0 mg/kg galantamine facilitated learning in young rabbits. Donepezil (3.0 mg/kg) did not facilitate learning in this experiment. However, both galantamine and donepezil reversed the deleterious effects of mecamylamine on learning. Significant differences in plasma and brain acetylcholinesterase levels were detected among the drug treatment groups. Fifteen daily injections did not produce statistically significant changes in nicotinic receptor binding in any of the five treatment groups. One possible interpretation of these results is that donepezil affected nicotinic acetylcholine receptors by raising the synaptic level of acetylcholine and hence, the probability of receptor activation, whereas galantamine bound to distinct allosteric sites not blocked by mecamylamine.

Use of natural zeolite to enhance nitrification in biofilter.

To enhance nitrification, natural zeolite and activated carbon were tested as a media in a biofilter to treat wastewater containing relatively high concentrations of TKN. Using those media, the adsorption isotherms for ammonium ion were compared; the K values for natural zeolite and activated carbon were found to be 0.5117 and 0.0006, respectively. In comparison of the performance of the two media, two identical, lab-scale biofilters were then operated for 4 months. The effect of NH3-N loading rates on the performance was investigated. The results showed that higher NH3-N removal efficiency and faster nitrification were achieved in the biofilter with natural zeolite throughout the experimental period. Nitrosomonas and Nitrobacter, two principal nitrifiers, in biofilm grown on two different media were counted and compared. Nitrobacter which is the more fragile of the two principal nitrifiers was outgrown in the biofilm on natural zeolite media. The reason for this may be due to the ammonium ion exchanging capacity of natural zeolite which provided the favorable environment for Nitrobacter.

MRI-assessed volume of cerebellum correlates with associative learning.

Richard F. Thompson's cerebellar model of classical eyeblink conditioning highlights Purkinje cells in cerebellar cortex and principal cells in the deep cerebellar nucleus as the integrating cells for acquisition of conditioned responses (CRs). CR acquisition is significantly slower in rabbits with lesions to cerebellar cortex and in Purkinje cell-deficient mice that lose all cerebellar cortical Purkinje cells. Purkinje cells are the largest neurons in the cerebellum and contribute significantly to cerebellar volume. Magnetic resonance imaging (MRI) was used to assess cerebellar volume in humans. Cerebellar volume was related to eyeblink conditioning (400-ms delay procedure) in 8 adults (21-35 years) and compared to 8 older adults (77-95 years) tested previously (Woodruff-Pak, Goldenberg, Downey-Lamb, Boyko, & Lemieux, 2000). In the young adult sample, there was a high correlation between percentage of CRs in a session and cerebellar volume (corrected for total intracranial volume [TIV], r =.58, p =.066). There were statistically significant age differences in cerebellar volume, t(14) = 8.96, p <.001, and percentage of CRs, t(14) = 3.85, p <.002, but no age difference in TIV. Combining the young and older adult sample, the correlation between percentage of CRs and cerebellar volume (corrected for TIV) was.832 (p <.001). Cerebellar volume showed age-related deficits likely due to Purkinje cell loss. Individual differences in classical eyeblink conditioning are associated with differences in cerebellar volume, supporting Thompson's model of a cerebellar cortical role in facilitating this form of associative learning.

Eyeblink classical conditioning differentiates normal aging from Alzheimer's disease.

Eyeblink classical conditioning is a useful paradigm for the study of the neurobiology of learning, memory, and aging, which also has application in the differential diagnosis of neurodegenerative diseases expressed in advancing age. Converging evidence from studies of eyeblink conditioning in neurological patients and brain imaging in normal adults document parallels in the neural substrates of this form of associative learning in humans and non-human mammals. Age differences in the short-delay procedure (400 ms CS-US interval) appear in middle age in humans and may be caused at least in part by cerebellar cortical changes such as loss of Purkinje cells. Whereas the hippocampus is not essential for conditioning in the delay procedure, disruption of hippocampal cholinergic neurotransmission impairs acquisition and slows the rate of learning. Alzheimer's disease (AD) profoundly disrupts the hippocampaL cholinergic system, and patients with AD consistently perform poorly in eyeblink conditioning. We hypothesize that disruption of hippocampal cholinergic pathways in AD in addition to age-associated Purkinje cell loss results in severely impaired eyeblink conditioning. The earliest pathology in AD occurs in entorhinal cortical input to hippocampus, and eyeblink conditioning may detect this early disruption before declarative learning and memory circuits become impaired. A case study is presented in which eyeblink conditioning detected impending dementia six years before changes on other screening tests indicated impairment. Because eyeblink conditioning is simple, non-threatening, and non-invasive, it may become a useful addition to test batteries designed to differentiate normal aging from mild cognitive impairment that progresses to AD and AD from other types of dementia.