► We develop an algorithm for computing spike-time distance in multiple dimensions. ► We also develop a method to estimate point pattern prototypes in multiple dimensions. ► The methods are applied ...to spike trains of feline responses to an acoustic stimulus. ► We find evidence that short latency responses were sensitive to behavioral state. ► These differences do not appear to be a byproduct of variation between animals.
The spike-time distance metric and the prototype of a collection of point patterns can be used to provide a metric description of repeated observations of point processes. Due to algorithmic limitations in computing spike-time distance, previous work in determining approximations of the prototype has largely been limited to single dimensional or small data sets. We develop new algorithms for each of these methods that are suitable for larger data sets. The first, an incremental matching algorithm, is a method to compute spike-time distance. The second algorithm involves the use of kernel smoothing for prototype construction. These methods readily extend to multiple dimensions and to marked point processes. We use a combination of these approaches to analyze neuronal spike data of cats in different behavioral states and across animals, and we compare our results to previous time series analyses that used averaged frequency histograms. Evidence is found for short latency responses to the acoustic CS that were sensitive to behavioral state.
A prospective study to evaluate short term changes in occlusal force and contact surface area associated with retainer wear. Thirty-two subjects, randomly assigned to two experimental groups, a clear ...overlay group and a wrap-around retainer group, were followed to assess occlusal changes. Assessments were made utilizing the T-Scan II (Tekscan, Inc., 307 West First St., South Boston, MA 02127) method of occlusal analysis at 3 time periods; T0 , at debond all subjects received lower fixed canine to canine retainer and upper clear overlay retainers; T1 , two weeks later 14 subjects received wrap-around retainers and the clear overlay retainer group was checked (18 subjects); T2 , occlusal contact assessment two months later for both groups. During T0 -T1 , the occlusion with clear overlay retainers showed a significant decrease in posterior surface area contact (p<0.05) as well as a decrease in force that was not statistically significant. During the following 6 weeks (T1 -T2 ), the Wrap-around retainer showed significant increases in posterior force and area (p<0.001). However, overall during time period T0 -T2 neither retainer group showed a significant change in relative distribution of occlusal force or surface area (p>0.05). An independent sample (15 subjects) showed high intraclass correlations (r>0.90) between replicate measurements of relative force, indicating low technical errors when multiple measurements are used. In conclusion, there were no significant net changes in occlusal forces or areas after six weeks of comparison between the wrap-around and clear overlay retainers following orthodontic therapy. In addition, it was shown that the T-Scan is a reliable apparatus for analysis of relative force.
Recordings of activity were made from 647 single units of the A
I cortex of awake cats to evaluate behavioral state-dependent changes in the population response to a 70-dB click. Averages of PST ...histograms of unit activity were used to assess the changes in response. This report focuses on slow components of the responses disclosed by averages employing bin widths of 16 ms. Responses were compared before and after a Pavlovian blink CR was produced by forward pairing of click conditioned stimuli (CSs) with USs. A backward-paired 70-dB hiss was presented as a discriminative stimulus. Studies were also done after backward pairing of the click CSs (backward conditioning) that produced weak sensitization instead of a conditioned response. There were four main findings. First, components of activity elicited 32–160 ms after presenting the hiss decreased significantly after conditioning and after backward conditioning. The decreases after conditioning represented the most pronounced changes in activity evoked by either clicks or hisses in this behavioral state. Second, baseline firing decreased after both conditioning and backward conditioning. The direction of baseline change was opposite that found in adjacent cortical regions and in A
I cortex after operant conditioning employing an acoustic cue. Third, prior to conditioning, unit activity in response to the hiss declined before the sound of the hiss reached its peak or terminated. This decrease was thought to represent a habituatory adaptation of response to a prolonged acoustic stimulus. This type of habituation to a lengthy stimulus has been recognized, behaviorally, but has not been observed previously in the activity of units of the auditory receptive cortex. Fourth, the percentage of click responsive units did not change significantly after the click was used as a CS for conditioning, and despite the accompanying changes in baseline activity, the absolute levels of activity summed in the first 16 ms after click delivery remained stable across behavioral states in which the motor response to the click was altered profoundly. The onset of the conditioned motor response began 20 ms after the click, and was shown earlier to depend on rapid, potentiated transmission through the cochlear nucleus and motor cortex for its generation. Thus the stability of the response to the click in the primary auditory receptive cortex was unexpected. This led us to make further analyses of the data with 2- and 4-ms bin widths (see companion report) that eventually disclosed a potentiated response to the click. The findings show stability and change in the response to the click as a CS, depending on the band pass (bin width) used for analysis of spike activity. In the representation disclosed by low pass filtering in this study, the response was stable. This representation provided information suitable for identifying commonalties of the click signals across varying behavioral states. The representations of the click and hiss contained in the slow components of the population response in the A
I cortex were uncorrelated with the selective potentiation of activity in motor cortex and behavioral performance in response to click as a CS after conditioning. Although changes in the activity evoked by hisses occurred after conditioning, the changes also occurred after backward conditioning when only small, sensitized behavioral responses to clicks and hisses were observed. Basic theoretical considerations about information transmission in complex neural networks plus clinical observations comparing derangements of linguistic and non-linguistic cortical functions in humans suggest that multiple representations of conditioned stimulus inputs may exist in local populations of cortical neurons. Together, our studies provide evidence for two different, concurrent representations of information about a click CS encoded in the spike activity of the A
I cortex.
Fast Radio Bursts (FRBs) are a powerful and mysterious new class of transient that are luminous enough to be detected at cosmological distances. By associating FRBs to host galaxies, we can measure ...intrinsic and environmental properties that test FRB origin models, in addition to using them as precise probes of distant cosmic gas. The Deep Synoptic Array (DSA-110) is a radio interferometer built to maximize the rate at which it can simultaneously detect and localize FRBs. Here, we present the first sample of FRBs and host galaxies discovered by the DSA-110. This sample of 11 FRBs is the largest, most uniform sample of localized FRBs to date, as it is selected based on association to host galaxies identified in optical imaging by Pan-STARRS1. These FRBs have not been observed to repeat and their radio properties (dispersion, temporal scattering, energy) are similar to that of the known non-repeating FRB population. Most host galaxies have ongoing star formation, as has been identified before for FRB hosts. Two hosts of the new sample are massive, quiescent galaxies. The distribution of star-formation history across this host-galaxy sample shows that the delay-time distribution is wide, with a powerlaw model that spans from \(\sim100\)\,Myr to \(\gtrsim2\)\,Gyr. This requires the existence of one or more progenitor formation channels associated with old stellar populations, such as the binary evolution of compact objects.
The Makgadikgadi Pans in northern Botswana are the desiccated relicts of a former major inland lake system, with fossil shorelines preserved at five distinct elevations (approximately 995 m, 945 m, ...936 m, 920 m and 912 m). These lakes persisted in the Makgadikgadi Basin, which evolved in the Okavango-Makgadikgadi Rift Zone: the south-western extension of the East African Rift System (EARS) into northern Botswana. This paper synthesizes cross-disciplinary evidence, which reveals that the antiquity of this lake complex has been widely underestimated. It presents a Regional Drainage Evolution Model that invokes tectonically initiated drainage reorganizations as the underlying control over lake evolution. Lake formation was initiated by rift-flank uplift along the Chobe Fault, across the course of the Zambezi River, which diverted the regional drainage net into the Makgadikgadi Basin. Filling of the basin initiated a major climatic feedback mechanism that locally increased rainfall and lowered evaporation rates. This progressively enhanced water input to the basin, and most likely led to overtopping of the Chobe Horst barrier during the three highest lake stands, with outflow into the Zambezi River. During this period, the hydrology of the basin would have been closely analogous to modern, shallow Lake Victoria. Fragmentation of the regional drainage network by successive river captures resulted in sequential contractions of the lake to lower elevation shorelines. In turn, resultant decreases in areas of these successive lakes modulated the magnitude of the feedback mechanism. Thus, loss of the Upper Chambeshi catchment caused the lake to drop from the 990 to the 945 m level. Severance of the former link between the Kafue and Zambezi resulted in a further drop to the 936 m shoreline. Inflow declined further after the impoundment of a major lake (Palaeo-Lake Bulozi) on the Upper Zambezi River, causing contraction to the 920 m shoreline. Continued incision of the Zambezi channel into the Chobe horst barrier ultimately terminated input from this river to the Makgadikgadi depression, causing contraction of the lake below 920 m, sustained by the Cuando and Okavango prior to final desiccation. This Regional Drainage Evolution Model contradicts previous proposals that have invoked Late Pleistocene climatic forcing to explain inferred fluctuations in lake levels. The timeframe developed for the drainage reorganizations requires that the lake was initiated by approximately 1.40 to 0.51 Ma at the most recent (Early - Mid-Pleistocene), while archaeological evidence shows that it had contracted below the 936 m shoreline before 500 ka. This contrasts with 14C and quartz luminescence dates (generally <100 ka), which require that the 945 m lake stage was extant during much of the Upper Pleistocene. The calcareous radiocarbon dates reflect multiple episodes of calcrete formation, while the young luminescence dates are ascribed to the extensive bioturbation of older Kalahari landforms.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The purpose of this study was to compare internal Morse taper connections in 2 separate modes: repeated torque/reverse-torque values and compressive bending at a 30-degree off-axis angle.
Three ...sample groups (n = 12 in each group)--a solid-screw implant paired with a 5.5-mm solid abutment (SSI), a synOcta implant with a 5.5-mm solid abutment (SOI), and a synOcta implant with a synOcta 5.5-mm solid abutment (SOSA)--were torqued to 35 Ncm, and the reverse torque to remove the abutment was recorded. This was repeated for 3 trials. Additionally, the sample groups were loaded 30 degrees off-axis, and the ultimate compressive values were recorded.
There was a significant difference in the initial reverse-torque values. The SOSA setup showed significantly lower torque than the SOI and SSI setups (P < .05). In addition, the compressive bending test showed that the SOSA setup was significantly different (P < .05) from the SSI and SOI setups. Radiographic survey of the test groups following compressive bending revealed no implant fractures, but bending of the implant-abutment complex occurred.
The alteration within the Morse taper did not reduce the strength of the implant-abutment connection, ie, the reduction in surface area did not significantly reduce the torque properties or tensile properties. The new 2-piece synOcta 5.5-mm solid abutment was shown to have a stronger implant-abutment connection when torqued down a second time.
In this in vitro study, alteration of the Morse taper with an internal octagon indexing did not significantly reduce the strength of the implant connection. Sufficient strength was exhibited, which would indicate this implant-abutment design for anterior as well as posterior edentulous sites.
Although need, opportunity, and funding for prevention programs are currently increasing, social workers do not appear to be leaders in this area of practice. Their lack of initiative in prevention ...will not likely change until social work education incorporates concepts from prevention science into the curriculum. This article: identifies and explains major prevention concepts and principles; discusses their congruence with social work's historical roots and current curriculum policy; and offers thoughts on integrating prevention values and content into both generalist and advanced courses. An appendix of resources is included to encourage faculties to consider how prevention could fit in the overall design of their programs.
Although instructors express concerns about social work students' writing skills, little research has been conducted. One remedy is a social work-focused writing course. This study assessed a ...required writing course with a sample of 49 baccalaureate students. From online pre- and posttest surveys, 2 student outcomes improved significantly: self-reported scores for writing self-efficacy and competence in course objectives. On-demand writing samples improved significantly based on anonymous ratings by the course instructors; however, blind ratings found gains but not at a significant level. Improved outcomes were not associated with demographic or background characteristics. We discuss limitations of the study and implications for social work education.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NMLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
As the terminology for sexual addiction/hypersexuality has evolved since the 1980s, social workers can benefit from an update and practice guidance. Although professional controversy continues about ...the symptoms, psychological mechanisms, and existence of the problem, the debate has come to a head with the official proposal of Hypersexual Disorder submitted for the new Diagnostic and Statistical Manual of Mental Disorders DSM-V. This article synthesizes information most relevant to social work practitioners, including efforts to name and conceptually describe the problem and its psychological mechanisms, clinical presentation, and practice guidance for social workers in various roles, including referral, assessment, and treatment.
We present updated constraints on the cosmological 3D power spectrum of carbon monoxide CO(1-0) emission in the redshift range \(2.4\)-\(3.4\). The constraints are derived from the two first seasons ...of Carbon monOxide Mapping Array Project (COMAP) Pathfinder line-intensity mapping observations aiming to trace star-formation during the Epoch of Galaxy Assembly. These results improve on the previous Early Science (ES) results through both increased data volume and improved data processing methodology. On the methodological side, we now perform cross-correlations between groups of detectors (''feed-groups''), as opposed to cross-correlations between single feeds, and this new feed-group pseudo power spectrum (FGPXS) is constructed to be more robust against systematic effects. In terms of data volume, the effective mapping speed is significantly increased due to an improved observational strategy as well as better data selection methodology. The updated spherically- and field-averaged FGPXS, \(\tilde{C}(k)\), is consistent with zero, at a probability-to-exceed of around \(34\,\%\), with an excess of \(2.7\,\sigma\) in the most sensitive bin. Our power spectrum estimate is about an order of magnitude more sensitive in our six deepest bins across \({0.09\,\mathrm{Mpc}^{-1} < k < 0.73\,\mathrm{Mpc}^{-1}}\), as compared to the feed-feed pseudo power spectrum (FPXS) of COMAP ES. Each of these bins individually constrains the CO power spectrum to \({kP_\mathrm{CO}(k)< 2400-4900\,\mathrm{\mu K^2 Mpc^{2}}}\) at \(95\,\%\) confidence. To monitor potential contamination from residual systematic effects, we analyze a set of 312 difference-map null tests and find that these are consistent with the instrumental noise prediction. In sum, these results provide the strongest direct constraints on the cosmological 3D CO(1-0) power spectrum published to date.
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