Potential sources of the 1995 Venezuelan equine encephalitis subtype IC epidemic

Venezuelan equine encephalitis viruses (VEEV) belonging to subtype IC have caused three (1962-1964, 1992-1993 and 1995) major equine epizootics and epidemics. Previous sequence analyses of a portion of the envelope glycoprotein gene demonstrated a high degree of conservation among isolates from the 1962-1964 and the 1995 outbreaks, as well as a 1983 interepizootic mosquito isolate from Panaquire, Venezuela. However, unlike subtype IAB VEEV that were used to prepare inactivated vaccines that probably initiated several outbreaks, subtype IC viruses have not been used for vaccine production and their conservation cannot be explained in this way. To characterize further subtype IC VEEV conservation and to evaluate potential sources of the 1995 outbreak, we sequenced the complete genomes of three isolates from the 1962-1964 outbreak, the 1983 Panaquire interepizootic isolate, and two isolates from 1995. The sequence of the Panaquire isolate, and that of virus isolated from a mouse brain antigen prepared from subtype IC strain P676 and used in the same laboratory, suggested that the Panaquire isolate represents a laboratory contaminant. Some authentic epizootic IC strains isolated 32 years apart showed a greater degree of sequence identity than did isolates from the same (1962-1964 or 1995) outbreak. If these viruses were circulating and replicating between 1964 and 1995, their rate of sequence evolution was at least 10-fold lower than that estimated during outbreaks or that of closely related enzootic VEEV strains that circulate continuously. Current understanding of alphavirus evolution is inconsistent with this conservation. This subtype IC VEEV conservation, combined with phylogenetic relationships, suggests the possibility that the 1995 outbreak was initiated by a laboratory strain.     

Evaluation of aerial sampling methods for detecting waterbird colonies

ABSTRACT Estimating the number of waterbird colonies in a given area can have important conservation implications, including assessment of the regional or global importance of an area and the impacts of conservation efforts (e.g., habitat restoration) and human disturbance (e.g., oil spills). Our objective was to examine differences in estimates of the number of waterbird colonies determined using strip‐transect (ST) surveys, distance sampling, and adaptive cluster sampling (ACS), and to compare these estimates to the minimum number of known colonies (MNKC) obtained using point‐to‐point surveys. We conducted aerial surveys in May 2004 and May and June 2005 at two sites in southern Louisiana: the Atchafalaya Basin (AB), a large forested wetland, and the Barataria‐Terrebonne estuary (BTE), a large coastal marsh with isolated clumps of woody vegetation suitable for nesting. In AB, we detected nine and eight colonies using the ACS and ST/distance sampling methods, respectively. Neither ACS estimator of number of colonies (Horvitz–Thompson and Hansen–Hurwitz) was within the 95% confidence interval of the estimate determined from ST; ST estimated—two to three times more colonies than either ACS estimator. The MNKC for the AB was 33, well within the 95% confidence interval of ? by ST sampling. For the BTE, ACS estimators (?_HT= 20.49, CI = 9.3–31.7; ?_HH= 14.15, CI = 2.3–26.0) were similar to the MNKC (20), whereas the ST (?= 87.94, CI = 82.9–92.9) and distance sampling (?= 60, CI = 31–113) methods produced much larger estimates. Our results suggest that the ACS method performed better when waterbird colonies were spatially clumped (BTE) and the ST method performed better in areas where colonies were more uniformly distributed (AB). Depending on management objectives, a complete, systematic survey of a study area may be required if the potential for missing large colonies is unacceptable. If surveying an area with no previous information about colony location or dispersion, we recommend a coarse‐scale analysis of the availability and contiguity of habitat likely to contain waterbird colonies; this analysis will help determine the most appropriate survey method.     

Rotating horizontal ground reaction forces to the body path of progression

When studying the biomechanics of a transient turn, the orientation of the body will change relative to the orientation of the force plates over the progression of the turn. To express ground reaction forces relative to the body, this study investigated possible origin locations and axis alignments of body reference frames. The gait patterns of 10 subjects were recorded as subjects negotiated a 90 degrees hallway corner. Body reference frames were chosen whose origins were the center of mass (COM) and the pelvis origin (PEL). A finite-difference method was used to align the axes of the reference frames according to the horizontal paths of the COM and PEL. The ground reaction impulses (GRIs) were calculated relative to the COM and PEL reference frames. GRI differences were small between the PEL and COM frames, suggesting that either is acceptable for turning studies. Based on an investigation of finite-difference parameters, the COM frame should be used when using a kinematic sampling rate of 60 Hz. Either frame is acceptable when sampling at higher rates.     

Trends in the Supply and Distribution of Physicians in Saskatchewan: January 1962 to June 1964

Using all the readily available sources of information, a study was designed to describe the changes in supply and distribution of physicians in Saskatchewan during the inception of the Province''s controversial Medical Care Insurance Act. Baselines were obtained in January 1962, and comparisons made in June 1963 and June 1964. The physician:population ratio was 1:1037 in January 1962 and 1:980 in June 1964. The average yearly physician turnover rate of 10% was exceeded in 1960 and in 1961 and then levelled off. The levelling off continued from January 1962 to June 1963. But between June 1963 and June 1964 the total number of physicians was sufficient both to re-establish the rising trend of the previous decade and to offset some of the losses of 1960-1962.     

New evidence for the polycentric evolution of Homo sapiens

The present author published, in 1962 and 1964, a hypothesis according to which modern-type man came into existence independently, in that least three separate geographic centres, during the Upper Pleistocene. New fossil finds corroborate two statements made in previously published papers: (a) Djebel Sahaba shows that recent negroids are modified ancient europoids, and (b) the Palaeosiberian affinities of Wadi-el-Amud indicate the early separation of mongoloid race ancestors at the Palaeanthropic phase.     

A Note on RAO's Inclusion Probability Proportional to size Sampling Scheme

A sufficient condition that the variance of HORVITZ -THOMPSON estimator for RAO 's (1965) inclusion probability proportional to sizes sampling scheme of selecting two units is uniformly smaller than that of RAO , HARTLEY and COCHRAN (1962) estimator has been obtained.     

Effects of News Frames on Perceived Risk,Emotions, and Learning

The media play a key role in forming opinions by influencing people´s understanding and perception of a topic. People gather information about topics of interest from the internet and print media, which employ various news frames to attract attention. One example of a common news frame is the human-interest frame, which emotionalizes and dramatizes information and often accentuates individual affectedness. Our study investigated effects of human-interest frames compared to a neutral-text condition with respect to perceived risk, emotions, and knowledge acquisition, and tested whether these effects can be "generalized" to common variants of the human-interest frame. Ninety-one participants read either one variant of the human-interest frame or a neutrally formulated version of a newspaper article describing the effects of invasive species in general and the Asian ladybug (an invasive species) in particular. The framing was achieved by varying the opening and concluding paragraphs (about invasive species), as well as the headline. The core text (about the Asian ladybug) was the same across all conditions. All outcome variables on framing effects referred to this common core text. We found that all versions of the human-interest frame increased perceived risk and the strength of negative emotions compared to the neutral text. Furthermore, participants in the human-interest frame condition displayed better (quantitative) learning outcomes but also biased knowledge, highlighting a potential dilemma: Human-interest frames may increase learning, but they also lead to a rather unbalanced view of the given topic on a “deeper level”.     

An effortless procedure to align the local frame of an inertial measurement unit to the local frame of another motion capture system

Inertial measurement units (IMUs) offer great opportunities to analyze segmental and joints kinematics. When combined with another motion capture system (MCS), for example, to validate new IMU-based applications or to develop mixed systems, it is necessary to align the local frame of the IMU sensors to the local frame of the MCS. Currently, all alignment methods use landmarks on the IMU's casing. Therefore, they can only be used with well-documented IMUs and they are prone to error when the IMU's casing is small. This study proposes an effortless procedure to align the local frame of any IMU to the local frame of any other MCS able to measure the orientation of its local frame. The general concept of this method is to derive the gyroscopic angles for both devices during an alignment movement, and then to use an optimization algorithm to calculate the alignment matrix between both local frames. The alignment movement consists of rotations around three more or less orthogonal axes and it can easily be performed by hands. To test the alignment procedure, an IMU and a magnetic marker were attached to a plate, and 20 alignment movements were recorded. The maximum errors of alignment (accuracy±precision) were 1.02°±0.32° and simulations showed that the method was robust against noise that typically affect IMUs. In conclusion, this study describes an efficient alignment procedure that is quick and easy to perform, and that does not require any alignment device or any knowledge about the IMU casing.     

Monitoring population size of mammals using a spotlight-count-based abundance index: How to relate the number of counts to the precision?

Abundance indices are widely used to study changes in population size in wildlife management. However, a truly appropriate measure of precision is often lacking in such studies. Statistically, the two crucial issues regarding the use of an abundance index are sampling and observability, which lead one to consider two kinds of errors, namely sampling and observation errors. The purpose of this methodological paper is to relate the number of counts to the precision of an abundance index by introducing the Hansen–Hurwitz–Bershad model which takes into account both sampling and observation errors. We illustrate this statistical approach in the case of a European rabbit (Oryctolagus cuniculus) abundance index based on spotlight counts, for two fixed spatial sampling units located in different ecological contexts. We show (i) that the usual sampling variance estimator is a downward-biased estimator of the total variance of the abundance index, (ii) that the bias of the usual variance estimator does not decrease when increasing the sampling size, (iii) that correlated observation errors may have a dramatic impact on the total variance, especially when the sampling size increases. The acknowledgement that the (pure) sampling variance underestimates the total variance because of observation errors is a statistical result that is neither widely known nor appreciated by most wildlife ecologists. The magnitude of this underestimation may be important and, therefore, observation errors cannot be always considered as a priori negligible in assessing the precision of a count-based abundance index.     

Repeats of base oligomers as the primordial coding sequences of the primeval earth and their vestiges in modern genes

Summary Three outstanding properties uniquely qualify repeats of base oligomers as the primordial coding sequences of all polypeptide chains. First, when compared with randomly generated base sequences in general, they are more likely to have long open reading frames. Second, periodical polypeptide chains specified by such repeats are more likely to assume either -helical or -sheet secondary structures than are polypeptide chains of random sequence. Third, provided that the number of bases in the oligomeric unit is not a multiple of 3, these internally repetitious coding sequences are impervious to randomly sustained base substitutions, deletions, and insertions. This is because the recurring periodicity of their polypeptide chains is given by three consecutive copies of the oligomeric unit translated in three different reading frames. Accordingly, when one reading frame is open, the other two are automatically open as well, all three being capable of coding for polypeptide chains of identical periodicity. Under this circumstance, a frame shift due to the deletion or insertion of a number of bases that is not a multiple of 3 fails to alter the downstream amino acid sequence, and even a base change causing premature chain-termination can silence only one of the three potential coding units.Newly arisen coding sequences in modern organisms are oligomeric repeats, and most of the older genes retain various vestiges of their original internal repetitions. Some of the genes (e.g., oncogenes) have even inherited the property of being impervious to randomly sustained base changes.     

THE ULTRASTRUCTURE OF THE AVIAN EGGSHELL

By means of scanning electron microscopy the eggshells of a number of passerine and non-passerine wild birds have been investigated. Details and structures have been shown which were hitherto unrevealed by other methods. As suggested by Schmidt (1962a) and Tyler (1964a, 1966a), there is no crystallographic demarcation between cone and palisade layer. There are many vesicular holes in the palisade layer, the physiological significance of which is not yet understood. Bird groups, sometimes even bird species, show specific features of ultratexture of the eggshell by which, for instance, mimetic cuckoo eggs can be distinguished from the eggs of fosters. Other examples are given in which ultra-structure provides useful taxonomic evidence.     

Using helicopter counts to estimate the abundance of Himalayan tahr in New Zealand's Southern Alps

Estimating the abundance and density of mountain ungulates is difficult because of rugged and remote terrain, high elevations, and rapidly changing weather. Helicopter surveys could overcome these problems, but researchers have seldom applied helicopter-based survey methods at large spatial scales in mountain terrain. We used helicopters to count introduced Himalayan tahr (Hemitragus jemlahicus) at 117 plots, each of 4 km², in New Zealand's Southern Alps during 2016–2019. The sampling frame was 7,844 km² and we located the plots at the vertices of an 8-km grid superimposed over the sampling frame (i.e., a systematic random sampling design). We conducted 3 repeat counts at each plot during summer–autumn. We used the repeat counts to estimate tahr abundance and density, corrected for imperfect detection, using a dynamic N-mixture model for open populations. We estimated the population of tahr in the sampling frame using design-based, finite sampling methods and model-based inference procedures. The mean estimated density of tahr on each plot varied from zero to 31.7 tahr/km². The mean densities of tahr varied among management units, ranging from 0.3 to 10.7 tahr/km², and exceeded specified intervention densities in 6 of the 7 management units. The total design-based estimate of tahr abundance in the sampling frame was 34,500 (95% CI = 27,750–42,900), with a coefficient of variation (CV) of 0.11. The corresponding model-based estimate of total abundance was similar (34,550, 95% CI = 30,250–38,700) but was substantially more precise (CV = 0.06) than the design-based estimate. The precision of the estimates for the individual management units was also better than that of the design-based estimates, with CVs of <0.20 for all but 1 management unit. Our study provides a repeatable method for sampling mountain ungulates. More generally, robust estimation of abundance and density of mountain ungulates is possible by combining aerial surveys and open population models with an objective, probabilistic sampling design.     

Ranked Set Sub Sampling the Non Response Strata for Estimating the Difference of Means

The existence of missing observations when the difference of means is estimated determines the need of sub sampling among the non respondents. Ranked set sampling is used for sub sampling. The information provided on one of the variables by the non respondents at the first attempt permits to rank them. The behavior of a ranked set sampling model with respect to other alternattives is studied in this paper. An unbiased estimator is derived and its expected variance is obtained. The proposed model is compared with the use of simple random sampling and Two‐phase sampling for stratification.     

Markov Systematic Sampling

In this paper, a new systematic sampling scheme with Markovian behaviour which yields positive first order inclusion probabilities for all units and positive second order inclusion probabilities for all pairs of units is introduced. The suggested method has been compared with sample random sampling, stratified random sampling, linear systematic sampling and systematic sampling with two random starts for the populations exhibiting exponential trend, autocorrelatedness and randomness. Throughout the discussion, the sample size is assumed to be even and the population size is a multiple of the sample size. The suggested method works well for estimating a finite population total for the population exhibiting exponential trend.     

On Use of Distinct Respondents in Randomized Response Surveys

It is well known for direct response surveys (DR), where the responses are obtained from the respondents directly, that the sample mean, based on distinct units of a simple random sample selected with replacement (SRSWR) method, is more efficient than the sample mean based on all the units including repetition. In this paper, it is shown that a linear unbiased estimator based on distinct units is inadmissible for estimating a finite population mean when the sample is selected by an arbitrary with replacement (WR) sampling scheme and the responses are obtained independently by some RR technique. Efficiencies for a few linear unbiased estimators are compared under SRSWR sampling.     

a Reexamination of Spring Deposited Lithics from Blackwater Draw Locality N0.1

Abstract

Archaeological’ excavations at Blackwater Draw Locality No. 1 from 1962 to 1964 uncovered a number of spring conduits. Several of these contained very high concentrations of Paleo-Indian lithic materials, which exhibited a high polish on their surfaces. Investigations of this phenomenon (Haynes and Agogino 1966) have suggested thatthe distributions and concentration of lithics within spring conduits. are the result of intentional discard (possibly through ritual activity) by Paleo-Indians.     

Effect of Laterally Wedged Insoles on the External Knee Adduction Moment across Different Reference Frames

Objective

Biomechanical effects of laterally wedged insoles are assessed by reduction in the knee adduction moment. However, the degree of reduction may vary depending on the reference frame with which it is calculated. The purpose of this study was to clarify the effect of reference frame on the reduction in the knee adduction moment by laterally wedged insoles.

Methods

Twenty-nine healthy participants performed gait trials with a laterally wedged insole and with a flat insole as a control. The knee adduction moment, including the first and second peaks and the angular impulse, were calculated using four different reference frames: the femoral frame, tibial frame, laboratory frame and the Joint Coordinate System.

Results

There were significant effects of reference frame on the knee adduction moment first and second peaks (P < 0.001 for both variables), while the effect was not significant for the angular impulse (P = 0.84). No significant interaction between the gait condition and reference frame was found in either of the knee adduction moment variables (P = 0.99 for all variables), indicating that the effects of laterally wedged insole on the knee adduction moments were similar across the four reference frames. On the other hand, the average percent changes ranged from 9% to 16% for the first peak, from 16% to 18% for the second peak and from 17% to 21% for the angular impulse when using the different reference frames.

Conclusion

The effects of laterally wedged insole on the reduction in the knee adduction moment were similar across the reference frames. On the other hand, Researchers need to recognize that when the percent change was used as the parameter of the efficacy of laterally wedged insole, the choice of reference frame may influence the interpretation of how laterally wedged insoles affect the knee adduction moment.     

Sampling Techniques Influence Understory Plant Trajectories After Restoration: An Example from Ponderosa Pine Restoration

Abstract Although there is no one correct technique for sampling vegetation, the sampling design chosen may greatly influence the conclusions researchers can draw from restoration treatments. Considerations when designing vegetation sampling protocol include determining what sampling attributes to measure, the size and shape of the sampling plot, the number of replicates and their location within the study area, and the frequency of sampling. We installed 20 point‐intercept transects (50‐m long), 8 belt transects (10 × 50 m), 10 adapted Daubenmire transects (four 0.5 × 2‐m plots), and 4 modified‐Whittaker plots (20 × 50 m with smaller nested plots) in treatment and control units to measure understory herbaceous response in a forest restoration experiment that tested different treatments. Point‐intercept transects on average recorded at least twice as much plant cover as did adapted Daubenmire transects and modified‐Whittaker plots taken at the same location for all control and treatment units. Point‐intercept transects and adapted Daubenmire plots on average captured fewer rare and exotic species in the control and treatment units in comparison with the belt transects and modified‐Whittaker plots. Modified‐Whittaker plots captured the highest species richness in all units. Early successional understory response to restoration treatments was likely masked by the response of the herbaceous community to yearly climatic variation (dry vs. wet years). Species richness and abundance were higher in wet years than dry years for all control and treatment units. Our results illustrate that sampling techniques can greatly influence perceptions of understory plant trajectories and therefore the interpretation of whether restoration goals have been achieved. In addition, our results suggest that restoration monitoring needs to be conducted for a sufficient length of time so that restoration treatment responses can be detected.