Hemispheric asymmetries for global and local visual perception: Effects of stimulus and task factors.

Although neurological and physiological studies indicate a right hemisphere superiority in global processing and a left hemisphere superiority in local processing of Navon-type hierarchical letters (D. Navon, 1977), most investigations of lateralized perception in healthy participants report neither asymmetry. In 6 experiments the authors examined the influence of attentional demands, stimulus properties, and mode of response on perceptual asymmetries for global and local perception. Consistent with their theoretical predictions, asymmetries were more robust on divided- than focused-attention tasks and in response to stimuli in which local and global levels were equally salient compared with those with greater global than local saliency. Contrary to their prediction, perceptual asymmetries were not influenced by the complexity of the motor response. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

It's all in your head: Why is the body inversion effect abolished for headless bodies?

It has been recently argued that human bodies are processed by a specialized processing mechanism. Central evidence was that body inversion reduces recognition abilities (body inversion effect; BIE) as much as it does for faces, but more than for other objects. Here we showed that the BIE is markedly reduced for headless bodies and examined the reason for this unexpected finding. Two alternative hypotheses were examined. Either the BIE is reduced for any type of incomplete body, or the head plays a special role in discrimination of body posture. Results show that omission of other body parts (leg or arms) did not influence the magnitude of the BIE relative to complete bodies. Analogous manipulations with faces did not influence the magnitude of the face inversion effect. Importantly, similar to effects we found for headless bodies, discrimination abilities for upright bodies and the BIE were markedly reduced for complete bodies that did not differ in head posture. We conclude that intact discrimination of body posture relies heavily on the head position. Our findings also imply that the BIE and the face inversion effect may be generated by different mechanisms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

High levels of anticardiolipin antibodies in patients with abnormal embryo morphology who attended an in vitro fertilization program

Although it is unlikely that the legislative endeavors of 1996 and 1997 relating to the health care industry will be matched in 1998, implementing regulations of the Balanced Budget Act and the Health Insurance Portability and Accountability Act will predicate the successes or shortcomings of these new laws in 1998. It is important that NPs stay in close contact with their state legislators and Medicaid officers responsible for implementing the SCHIP. NPs should also closely track efforts at the Federal level to ensure inclusion of non-physician providers in legislation that is important to NPs, such as bans on "gag" clauses--a protection that should include all health care providers.     

Patients with Turner's syndrome may have an inherent endometrial abnormality affecting receptivity in oocyte donation

OBJECTIVE: To evaluate whether endometrial receptivity is compromised in patients with premature ovarian failure (POF) due to Turner's syndrome who undergo oocyte donation. DESIGN: Retrospective analysis. SETTING: In vitro fertilization-ET units, anonymous oocyte donation program. PATIENTS: The study included 53 patients with POF who underwent oocyte donation. These included 7 patients with Turner's syndrome (45,X) who underwent 22 ET cycles, 15 women with Turner variants (mosaics, deletions, or isochromosomes) who underwent 36 ET cycles, and 31 other patients with POF and a normal karyotype who underwent 69 oocyte donation cycles. INTERVENTION: All patients on standby for donation were treated with E2 valerate 6 mg/d until oocytes became available; then P 100 mg/d was added. Oocyte donors were healthy women < 34 years who underwent IVF themselves. MAIN OUTCOME MEASURES: Clinical pregnancy rates (PRs), biochemical pregnancies, early abortions, and delivery rates were evaluated. RESULTS: Turner's syndrome patients had a significantly higher rate of biochemical pregnancies (22.7% versus 4.3%), a lower clinical PR (22.7% versus 33.3%), a significantly higher rate of early abortions (60% versus 8.7%), and a significantly lower rate of deliveries per pregnancy (20.0% versus 73.1%) compared with non-Turner patients. CONCLUSIONS: Patients with a complete or partial deficiency of an X chromosome have reduced PRs and an increase in early implantation failure after oocyte donation. This may indicate an inherent endometrial abnormality, possibly associated with a deficiency of X-linked genes regulating endometrial receptivity.     

Using unsupervised incremental learning to cope with gradual concept drift

Current computational approach to incremental learning requires a constant stream of labelled data to cope with gradual environmental changes known as concept drift. This paper examines a case where labelled data are unavailable. Inspired by the performance of the human visual system, capable of adjusting its concepts using unlabelled stimuli, we introduce a variant to an unsupervised competitive learning algorithm known as the Leader Follower (LF). This variant can adjust pre-learned concepts to environmental changes using unlabelled data samples. We motivate the needed change in the existing LF algorithm and compare between two variants to enable the accumulation of environmental changes when facing unbalanced sample ratio.     

An efficient algorithm for minimizing earliness,tardiness, and due-date costs for equal-sized jobs

We consider a single-machine scheduling problem with equal-sized jobs. The objective is to minimize the maximum weighted earliness–tardiness and due-date costs. We present an algorithm to solve this problem. Our algorithm makes use of bottleneck jobs and priority queues, and has a computational complexity of O(n⁴logn)$O(n^4\log n)$. This complexity is a significant improvement of the existing algorithm in the literature.     

Uniform unweighted set cover: The power of non-oblivious local search

We are given $n$ base elements and a finite collection of subsets of them. The size of any subset varies between $p$ to $k$ ($p<k$). In addition, we assume that the input contains all possible subsets of size $p$. Our objective is to find a subcollection of minimum-cardinality which covers all the elements. This problem is known to be NP-hard. We provide two approximation algorithms for it, one for the generic case, and an improved one for the special case of $(p,k)=(2,4)$.The algorithm for the generic case is a greedy one, based on packing phases: at each phase we pick a collection of disjoint subsets covering $i$ new elements, starting from $i=k$ down to $i=p+1$. At a final step we cover the remaining base elements by the subsets of size $p$. We derive the exact performance guarantee of this algorithm for all values of $k$ and $p$, which is less than $H_k$, where $H_k$ is the $k$’th harmonic number. However, the algorithm exhibits the known improvement methods over the greedy one for the unweighted $k$-set cover problem (in which subset sizes are only restricted not to exceed $k$), and hence it serves as a benchmark for our improved algorithm.The improved algorithm for the special case of $(p,k)=(2,4)$ is based on non-oblivious local search: it starts with a feasible cover, and then repeatedly tries to replace sets of size 3 and 4 so as to maximize an objective function which prefers big sets over small ones. For this case, our generic algorithm achieves an asymptotic approximation ratio of $1.5+?$, and the local search algorithm achieves a better ratio, which is bounded by $1.458333\dots +?$.