cssi/SciSciGPT-SciSciNet huggingface dataset:
Electrospun formulation of acyclovir/cyclodextrin nanofibers for fast-dissolving antiviral drug delivery.

Abstract Acyclovir is an effective antiviral drug which suffers from limited water solubility and low bioavailability. However, it is possible to eliminate these limitations by forming inclusion complexes with cyclodextrins. In this study, we have reported the electrospinning of polymer-free and free-standing acyclovir/cyclodextrin nanofibers for the first time. This is a promising approach for developing a fast-dissolving delivery system of an antiviral drug molecule. Here, hydroxypropyl-beta-cyclodextrin (HP-βCD) was used as both complexation agent and electrospinning matrix. The acyclovir/HP-βCD system was prepared by incorporating ~7% (w/w) of acyclovir into the highly concentrated aqueous solution of HP-βCD (180%, w/v). The control sample of acyclovir/polyvinylpyrrolidone (PVP) nanofiber were also generated using ethanol/water (3/1, v/v) solvent system and the same initial acyclovir (7%, w/w) content. Due to the inclusion complexation, acyclovir/HP-βCD nanofibers provided better encapsulation and so loading efficiency. The loading efficiency of acyclovir/HP-βCD nanofibers was determined as ~98%, while it was ~66% for acyclovir/PVP nanofibers. It was found that acyclovir/HP-βCD nanofibers contained some crystalline form of acyclovir. Even so, it showed faster dissolving/release and faster disintegration profiles compared to acyclovir/PVP nanofibers which had higher amount of crystalline acyclovir. The inclusion complexation property and high water solubility of HP-βCD (> 2000 mg/mL) ensured the fast-dissolving property of acyclovir/HP-βCD nanofibers. Briefly, acyclovir/HP-βCD nanofibers are quite promising alternative to the polymeric based system for the purpose of fast-dissolving oral drug delivery. The enhanced physicochemical properties of drug molecules and the use of water during whole process can make drug/cyclodextrin nanofibers a favorable dosage formulation for the desired treatments.
Real Madrid and public relations: applying the circuit of culture to organizational values

Real Madrid is one of the leading sport organizations in the world in terms of finances, fans and awards, a status gained in large part due to its values. Using a critical/historical method, this p...
On binomial coefficients associated with Sierpi\'{n}ski and Riesel numbers

In this paper, we investigate the existence of Sierpinski numbers and Riesel numbers as binomial coefficients. We show that for any odd positive integer $r$, there exist infinitely many Sierpinski numbers and Riesel numbers of the form $\binom{k}{r}$. Let $S(x)$ be the number of positive integers $r$ satisfying $1\leq r\leq x$ for which $\binom{k}{r}$ is a Sierpinski number for infinitely many $k$. We further show that the value $S(x)/x$ gets arbitrarily close to 1 as $x$ tends to infinity. Generalizations to base $a$-Sierpinski numbers and base $a$-Riesel numbers are also considered. In particular, we prove that there exist infinitely many positive integers $r$ such that $\binom{k}{r}$ is simultaneously a base $a$-Sierpinski and base $a$-Riesel number for infinitely many $k$.
Zena Werb (1945-2020): Mourning the loss of a tissue microenvironment icon.

The science community has lost a unique voice, a fierce advocate for women in science, and a beloved mentor. Zena Werb, PhD, who was a Professor and Vice Chair in the Department of Anatomy for over 40 years, Associate Director for basic science at the University of California, San Francisco (UCSF) Helen Diller Family Comprehensive Cancer Center, and National Academy of Science member since 2015, died unexpectedly on June 16th, 2020 at the age of 75. Zena Werb ( Right ) and Mina Bissell ( Left ). Zena was an uncannily insightful, impressively intelligent, consistently honest, and refreshingly unpretentious scientist. These attributes can be traced back to her humble beginnings. Zena was born in early 1945 to Polish–Jewish parents in the Nazi concentration camp Bergen-Belsen in Germany. After the camp was liberated Zena’s mother carried her over the Swiss–Italian Alps to reunite with her father in Italy. Shortly thereafter the family joined countless refugees fleeing Europe to emigrate to Canada, where they initially settled in northern Saskatchewan. After a short stint in Saskatchewan the family relocated to a farm in southern Ontario, where Zena received her early education in a one-room schoolhouse. Notwithstanding these inauspicious beginnings, and no doubt due in large part to the fact that Zena’s parents were strong advocates of education, Zena developed an early love of math and science. Encouraged by her father Zena chose to study biochemistry at the University of Toronto, where she excelled … [↵][1]1To whom correspondence may be addressed. Email: mjbissell{at}lbl.gov. [1]: #xref-corresp-1-1
Rumination & eating psychopathology among trans and nonbinary individuals: A path analysis integrating minority stress.

Abstract Ruminative thought patterns, defined as repetitive negative self-focused attention, are considered an avoidant coping strategy for managing stress. As trans and nonbinary (TNB) individuals commonly experience prejudice and discrimination in response to their gender identities (i.e. minority stressors), rumination over these stressors may contribute to heightened risk of psychopathology in these groups. Although rumination is a general risk factor for eating disorder (ED) psychopathology, no studies to date have examined whether eating- or gender-related ruminative patterns relate to maintenance of ED psychopathology for TNB individuals. This cross-sectional study investigated whether levels of rumination (both gender-related and ED-specific) mediated the relationship between minority stress and ED psychopathology. Method Participants were 242 TNB adults (Mage = 24.92, SD = 6.5, Range = 18-70) recruited online, who completed measures of minority stress, gender-related rumination, ED-specific rumination, and ED psychopathology. We used Preacher-Hayes' approach to examine the parallel mediation model, with gender-related and ED-specific rumination as potential mediators. Results Gender-related rumination did not mediate the relation between gender minority stress and ED psychopathology, Indirect B = -0.00 [95% BCa CI: -0.01, 0.00]; however, ED-specific rumination was significant, indicating partial mediation, Indirect B = 0.01 [95% BCa CI: 0.00, 0.02]. Conclusion As gender minority stress and ED-specific rumination relate to ED psychopathology, it is essential that clinicians adopt an intersectional minority stress framework in understanding ED psychopathology among TNB individuals.
Acute depletion of CTCF rewires genome-wide chromatin accessibility.

Background The transcription factor CTCF appears indispensable in defining topologically associated domain boundaries and maintaining chromatin loop structures within these domains, supported by numerous functional studies. However, acute depletion of CTCF globally reduces chromatin interactions but does not significantly alter transcription. Results Here, we systematically integrate multi-omics data including ATAC-seq, RNA-seq, WGBS, Hi-C, Cut&Run, and CRISPR-Cas9 survival dropout screens, and time-solved deep proteomic and phosphoproteomic analyses in cells carrying auxin-induced degron at endogenous CTCF locus. Acute CTCF protein degradation markedly rewires genome-wide chromatin accessibility. Increased accessible chromatin regions are frequently located adjacent to CTCF-binding sites at promoter regions and insulator sites associated with enhanced transcription of nearby genes. In addition, we use CTCF-associated multi-omics data to establish a combinatorial data analysis pipeline to discover CTCF co-regulatory partners. We successfully identify 40 candidates, including multiple established partners. Interestingly, many CTCF co-regulators that have alterations of their respective downstream gene expression do not show changes of their own expression levels across the multi-omics measurements upon acute CTCF loss, highlighting the strength of our system to discover hidden co-regulatory partners associated with CTCF-mediated transcription. Conclusions This study highlights that CTCF loss rewires genome-wide chromatin accessibility, which plays a critical role in transcriptional regulation.
Oncolytic Virus Affects the RAS Pathway in Cancer: RNA Sequence Analysis.

Background Approximately 45% of individuals diagnosed with Colorectal Cancer (CRC) also possess KRAS mutations. One developing therapeutic method for this disease is reovirus treatment. It is theorized that reovirus treatment on patients with KRAS mutated CRC cells would be successful due to the virus' innate oncolytic properties [1]. Reovirus, a stable form of nonenveloped double-stranded RNA, causes minor infections in humans under normal circumstances. However, when the virus encounters KRAS mutated cells, it has the potential to lyse them [2]. While this method of treatment to CRC has shown signs of success, we are still some ways from universal administration of reovirus as a treatment. This review seeks to utilize various studies, as well as our original research data, to investigate reovirus as an efficient method of treatment, with a focus on select growth, apoptotic and RAS-related genes, and their effectiveness of mitigating KRAS mutated CRC post reovirus treatment. Furthermore, the review highlights transcriptome analysis as an effective tool to examine these genes and their activity. It has been shown that reovirus treatment induces apoptosis and mitigates growth related gene activity. Conclusions This review confirms the novelty of our findings on the efficacy of reovirus in CRC treatment. The study that this review article discusses concluded that 10 apoptotic and lymphocyte-related genes were found to be upregulated and 6 angiogenesis and Ras-related genes were found to be downregulated post reovirus treatment. These findings enforce the notion that reovirus could be used as a novel treatment for KRAS mutated CRC.
Long-Term Imaging of the Aorta: Considerations and Comparison of Modalities

Patients with aortic dissection and other acute aortic diseases are subject to long-term imaging surveillance to monitor aortic growth and detect complications. This chapter will focus on practical aspects of long-term aortic imaging, including the selection of imaging surveillance intervals, choice of imaging modality (echocardiography vs. CT vs. MRI) and highlight advantages and weaknesses of various imaging techniques for assessment of aortic disease progression. We will first review published data and recommendations for long-term imaging of acute aortic disease, highlight a variety of modality and patient-specific factors to guide selection of an imaging surveillance strategy, and discuss considerations for imaging surveillance after endovascular aortic repair. Furthermore, we will outline common measurement techniques for assessing disease progression with specific attention on pitfalls and sources of measurement variability, and lastly briefly highlight several emerging image analysis techniques that may improve the accuracy and efficiency of imaging surveillance.
Differential expression of somatostatin receptor subtypes in brain

The tetradecapeptide somatostatin has been implicated as an important regulator of neuronal and neuroendocrine function in the CNS. The cellular actions of somatostatin are mediated by specific receptors. The genes encoding two different somatostatin receptors (SSTRs) have been isolated and characterized, and RNA blotting studies have shown that both SSTR1 and SSTR2 are expressed in the brain. In order to gain a better understanding of the functions of somatostatin in the CNS, the distribution of SSTR1 and SSTR2 mRNAs was determined using the technique of in situ hybridization. SSTR1 mRNA was present throughout the mouse brain, particularly in the supra- and infragranular layers of the cortex, the amygdala, hippocampus, bed nucleus of the stria terminalis, substantia innominata, hypothalamus, pretectum, substantia nigra, parabrachial nucleus, and nucleus of the solitary tract. SSTR2 mRNA was primarily observed in the infragranular layers of the cortex, the amygdala, claustrum, endopiriform nucleus, arcuate and paraventricular nuclei of the hypothalamus, and medial habenular nucleus. Several regions of the brain reported to contain dense somatostatin-like immunoreactive terminal fields and receptor binding sites were devoid of both SSTR1 and SSTR2 mRNA, suggesting the existence of additional SSTR subtypes.
Rape in the District of Columbia

Abstract From July, 1969, through December, 1970, almost 1,200 female alleged victims of sexual assault were brought for medical examination at D. C. General Hospital. Ninety per cent alleged vaginal penetration. Coercion occurred with the use of threat, weapon, or physical injury, or threat was felt although only implied. Thirty per cent of attacks were by 2 or more males. The number of attacks per hour increased from the daytime, to the “swing shift”, to evening, to night. The alleged victims were 76 per cent Black. Ages of the victims ranged from 15 months to 82 years, with 63 per cent 18 years and over. Practically all assaults were by Black males, and 60 per cent were strangers to the victims. Fifteen women and girls had injuries requiring hospitalization; 58 with severe injuries and 33 with emotional trauma needed emergency room treatment. Follow-up by nurses provided emotional support and opportunity for patients to abreact the event. Patients brought for treatment included 61 with emotional disturbances, 53 with gonorrhea, and 15 for therapeutic abortions. Nine patients were hospitalized for emotional reactions and reactivations. In comparison to periods from September, 1965 through 1969, there were increases in complainants to the Sex Section and brought to initial medical examination, with a shift to older alleged victims; more were White and attacked by strangers, with injuries and emotional trauma. Constant reiteration made interns and residents aware of the latter. Because of a nursing shortage, follow-up was not as extensive, but a larger number and proportion of patients were brought to treatment for emotional disturbances, gonorrhea, and pregnancy.
Controlling The Lorenz System With Delay

A generalized method for adaptive control, synchronization of chaos and parameter identification in systems governed by ordinary differential equations and delay-differential equations is developed. The method is based on the Lagrangian approach to fluid dynamics. The synchronization error, defined as a norm of the difference between the state variables of two similar and coupled systems, is treated as a scalar fluid property advected by a fluid particle in the vector field of the controlled response system. As this error property is minimized, the two coupled systems synchronize and the time variable parameters of the driving system are identified. The method is applicable to the field of secure communications when the variable parameters of the driver system carry encrypted messages. The synchronization method is demonstrated on two Lorenz systems with variable parameters. We then apply the method to the synchronization of hyperchaos in two modified Lorenz systems with a time delay in one the state variables.
Trade‐offs between offspring fitness and future reproduction of adult female black brent

1. Successful reproduction requires numerous decisions, and some of which may require trade-offs between current and future reproduction. We studied effects of choice of foraging patches on gosling growth and future breeding by mothers in black brent (Branta bernicla nigricans) geese. 2. Specific foraging areas consistently produced high-quality goslings over 21 years. We found a consistent ranking of gosling mass, corrected for age, across brood rearing areas (BRAs) and years [Akaike model weights, Σw(i) = 1·00 for models including additive effects of BRA and year]. Growth of goslings largely determines their future fitness, so areas where goslings grew most rapidly also produced goslings with the highest mean fitness. 3. We used a multistate robust design capture-mark-recapture approach to estimate the probability of transitioning from a breeding state to a non-breeding (unobservable) state as a function of quality of BRA. 4. In the best supported model, transition from a breeding state to a non-breeding state was positively related to gosling growth rates across BRAs. Thus, future reproduction was lower for females using BRAs that produced higher-quality goslings. Our results are consistent with trade-offs by individual brent between fitness of their current offspring and their own reproductive value.
A decentralized approach to secure management of nodes in distributed sensor networks

Distributed sensor networks are a promising technology for surveillance and reconnaissance in many applications, such as next generation C4ISR and the digital battlefield. The dearth of effective security mechanisms are a main obstacle to the acceptance of distributed sensor networks. As research pushes sensor nodes to be smaller and ubiquitous, security issues become paramount. Security in sensor networks needs to be considered during the early phases of development. This paper describes a decentralized solution to the problem of securely checking node membership in ad hoc sensor networks. This method does not require each node to maintain a membership list, does not require communication between the base station and verifying node, and it efficiently handles dynamic membership events (node leaves and joins). It is based on the concept of quasi-commutative hash functions, also called one-way accumulators. The paper analyzes resource requirements and suggests new ways to optimize the use of one-way accumulators while maintaining security in sensor node applications.
On non-approximability for quadratic programs

This paper studies the computational complexity of the following type of quadratic programs: given an arbitrary matrix whose diagonal elements are zero, find x /spl isin/ {-1, 1}/sup n/ that maximizes x/sup T/Mx. This problem recently attracted attention due to its application in various clustering settings, as well as an intriguing connection to the famous Grothendieck inequality. It is approximable to within a factor of O(log n), and known to be NP-hard to approximate within any factor better than 13/11 - /spl epsi/ for all /spl epsi/ > 0. We show that it is quasi-NP-hard to approximate to a factor better than O(log/sup /spl gamma// n)for some /spl gamma/ > 0. The integrality gap of the natural semidefinite relaxation for this problem is known as the Grothendieck constant of the complete graph, and known to be /spl Theta/(log n). The proof of this fact was nonconstructive, and did not yield an explicit problem instance where this integrality gap is achieved. Our techniques yield an explicit instance for which the integrality gap is /spl Omega/ (log n/log log n), essentially answering one of the open problems of Alon et al. [AMMN].
Epstein-Barr Virus-Associated Atraumatic Spleen Laceration Presenting with Neck and Shoulder Pain.

Patient: Male, 15 Final Diagnosis: Infectious Mononucleosis induced spleen laceratio Symptoms: Fever • headache • neck pain and upper shoulder pain which was worse with flexion and extension Medication: — Clinical Procedure: Splenic angiogram and proximal splenic artery embolization technique Specialty: Critical Care Medicine Objective: Unusual clinical course Background: Infectious mononucleosis, caused by the Epstein-Barr virus (EBV), is a common infection with worldwide distribution; more than 90% of people have been infected by adulthood. One of the most feared, albeit rare, complications, occurring in less than 0.5% of those infected, is splenic injury or rupture. Case Report: A febrile 15-year-old male presented to the emergency department with the chief compliant of headache, neck pain, and upper shoulder pain. He did not recall any specific traumatic injury. His abdomen was soft, nondistended, and was tender in the right and left lower quadrants. Right lower quadrant ultrasound demonstrated non-visualization of the appendix, moderate right lower quadrant free fluid, and positive McBurney’s sign. CT of the abdomen and pelvis was ordered, which demonstrated moderate splenomegaly, with findings compatible with laceration through the anterior aspect of the spleen, with moderate hemoperitoneum. Monospot was negative and EBV panel demonstrated IGG negative, IGM positive, and, IGG negative. The patient was transferred to interventional radiology for a splenic angiogram and proximal splenic artery embolization. The angiogram demonstrated grade 3 laceration with moderate hemoperitoneum and no active extravasation or evidence of pseudoaneurysm. The patient was admitted and made a prompt recovery without any other sequelae. Conclusions: The presentation of splenic injury or rupture can vary; the patient may complain of abdominal pain or left upper quadrant pain, may exhibit referred left shoulder pain when the LUQ is palpated (Kehr’s Sign), or may exhibit hemodynamic instability. Given the spectrum of non-specific symptoms, diagnosing EBV-induced splenic laceration can be difficult.
Who are the peer reviewers and how much do they review

To assess the nature and work load of reviewers for the American Journal of Public Health , I surveyed a sample of 276 reviewers in the latter half of 1988, with a 96% response rate. Respondents reported reviewing papers for 274 other journals in 1987, 81% of which were monitored by the Science Citation Index or the Social Science Citation Index . They reviewed most often for The Journal of the American Medical Association (27%), the American Journal of Epidemiology (26%), and the New England Journal of Medicine (23%). The median number of journals for which they reviewed was 3.6, the median of their estimated review time was 2.7 hours, and the weighted average review time (adjusted for number of reviews) was 2.4 hours. The range of review time was broad and inversely related to the number of papers reviewed. Respondents donated an estimated 3360 hours of uncompensated labor to the American Journal of Public Health in 1987, and a total of 6439 hours (26.8 hours per reviewer) to reviewing for all journals. Of the reviewers for the American Journal of Public Health , only 31% were not listed as an author of a source publication in the 1987 Science Citation Index and only 15% were not cited. ( JAMA . 1990;263:1338-1340)
Identification of Selective Inhibitors for the Glycosyltransferase MurG via High-Throughput Screening

Nucleotide-glycosyltransferases (NDP-Gtfs) play key roles in a wide range of biological processes. It is difficult to probe the roles of individual glycosyltransferases or their products because, with few exceptions, selective glycosyltransferase inhibitors do not exist. Here, we investigate a high-throughput approach to identify glycosyltransferase inhibitors based on a fluorescent donor displacement assay. We have applied the screen to E. coli MurG, an enzyme that is both a potential antibiotic target and a paradigm for a large family of glycosyltransferases. We show that the compounds identified in the donor-displacement screen of MurG are selective for MurG over other enzymes that use similar or identical substrates, including structurally related enzymes. The donor displacement assay described here should be adaptable to many other NDP-Gtfs and represents a new strategy to identify selective NDP-Gtf inhibitors.
Hyaluronidase Activity of Human Hyal1 Requires Active Site Acidic and Tyrosine Residues

Hyaluronidases are a family of endolytic glycoside hydrolases that cleave the β1-4 linkage between N-acetylglucosamine and glucuronic acid in hyaluronan polymers via a substrate-assisted mechanism. In humans, turnover of hyaluronan by this enzyme family is critical for normal extracellular matrix remodeling. However, elevated expression of the Hyal1 isozyme accelerates tumor growth and metastatic progression. In this study, we used structural information, site-directed mutagenesis, and steady state enzyme kinetics to probe molecular determinants of human Hyal1 function. Mutagenesis of active site residues Glu131 and Tyr247 to Gln and Phe, respectively, eliminated activity at all hyaluronan concentrations (to 125 μm or 2.5 mg/ml). Conservative mutagenesis of Asp129 and Tyr202 significantly impaired catalysis by increases of 5- and 10-fold in apparent Km and reductions in Vmax of 95 and 50%, respectively. Tyr247 and Asp129 are required for stabilization of the catalytic nucleophile, which arises as a resonance intermediate of N-acetylglucosamine on the substrate. Glu131 is a likely proton donor for the hydroxyl leaving group. Tyr202 is a substrate binding determinant. General disulfide reduction had no effect on activity in solution, but enzymatic deglycosylation reduced Hyal1 activity in a time-dependent fashion. Mutagenesis identified Asn350 glycosylation as the requisite modification. Deletion of the C-terminal epidermal growth factor-like domain, in which Asn350 is located, also eliminated activity, irrespective of glycosylation. Collectively, these studies define key components of Hyal1 active site catalysis, and structural factors critical for stability. Such detailed understanding will allow rational design of enzyme modulators.
The Pathology of Paraphrenia

The term paraphrenia refers to a condition characterized by a strong delusional component with preservation of thought and personality. Most affected patients are women. Although a late age at onset (> 60 years) has been proposed in the literature, evidence for this assertion remains debatable. Deterioration of cognitive functions occurs very slowly but may lead to mild dementia over a period of years. Pathological studies indicate the presence of neurofibrillary tangles (NFTs), primarily within the entorhinal cortex. Compared with the severity of neuritic changes, amyloid deposition remains scant. Pyramidal cells affected by NFTs appear to be preserved. Both the clinical history and neuropathology of paraphrenia are similar to those aspects described for NFT-predominant senile dementia. Risk factors, including organic lesions, may precipitate an earlier onset of symptomatology in patients exhibiting this pathology. Many of the symptoms in paraphrenia can be explained by involvement of the entorhinal cortex.
Strongly correlated electronic systems with one hole: Dynamical properties

The spectral functions of one hole in the t-J and one-band Hubbard models are calculated using exact diagonalization techniques on small lattices. Results for the t-${\mathit{J}}_{\mathit{z}}$ model are also presented. For the t-J model we found that there is a quasiparticle at the bottom of the hole spectrum with an energy well approximated by ${\mathit{E}}_{\mathit{h}}$=-3.17+2.83${\mathit{J}}^{0.73}$ (for 0.1\ensuremath{\le}J\ensuremath{\le}1.0, t=1) on a 4\ifmmode\times\else\texttimes\fi{}4 lattice. The rest of the spectrum is not incoherent: We identified at least two other peaks following a similar power-law behavior with J. We speculate that the J dependence of the results can be explained by a model where the hole is trapped in a confining potential as in the Ising limit. The bandwidth of the hole is linear in J in the region 0.1\ensuremath{\le}J\ensuremath{\le}0.4 although a power-law behavior is not excluded. The spectral weight of the quasiparticle grows like ${\mathit{J}}^{0.5}$ in the same region. We present new analytical results in the large J/t limit to understand the motion of the hole: In perturbation theory it can be shown that the momentum of the hole at large J/t is k=(\ensuremath{\pi},\ensuremath{\pi}) changing to k=(\ensuremath{\pi}/2,\ensuremath{\pi}/2) at intermediate J/t in agreement with numerical and spin-waves results. We show analytically and numerically that the bandwidth of the quasiparticle is of order t in the large J/t limit. This result corresponds to a spin-liquid state. The one-hole spectral function of the Hubbard model is obtained for lattices with 8 and 10 sites. A quasiparticle is also observed in this case. The bandwidth and the relation with the t-J model are discussed and a comparison with recent Monte Carlo results is made. We also review and extend previous results for the ground-state properties of the t-J model.
Static thread mapping for NoCs via binary instrumentation traces

A novel methodology is proposed for thread mapping on a chip-multiprocessor (CMP) system with a network-on-chip (NoC). This novel mapping leverages multi-threaded traces produced by a binary instrumentation tool, which classifies the communication and computation events for each thread of a multi-threaded program application. Processing these binary instrumentation traces after profiling, a static thread mapping is computed to improve the NoC performance.
Morphometric comparison of the acute rabbit corneal response to 1540-nm laser light following in-vitro exposure to millisecond or nanosecond pulse widths

Significant damage to rabbit corneal tissue was produced by a single pulse, in vitro exposure of 1540 m infrared laser light operating in either millisecond or nanosecond pulse widths. Millisecond pulse widths of infrared laser light produced a marked coagulative necrosis of both the corneal epithelium and stroma. We also noted histologic alterations in the stromal matrix within the beam path that we interpreted as matrix remodeling. To test this interpretation, we used an indirect immunohistochemical procedure to detect Matrix Metalloproteinase-2 (MMP-2) activity. Immunohistochemistry revealed that the MMP-2 reaction was mostly limited to the margins of the beam path. In addition, the MMP-2 reaction was less intense than expected given the significant tissue changes observed in the histologic sections. Exposure of rabbit corneal tissue to the nanosecond pulse widths produced a less severe coagulative necrosis of the tissue when compared to the millisecond exposures. However, a markedly stronger immunohistochemical pattern than would have been predicted from the histologic sections was observed, with approximately half of the beam path filled with MMP-2 reaction product. These data suggest an association between infrared laser pulse width and the degree of extracellular matrix remodeling in rabbit corneal tissue.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Effect of yeast extract on alpha-amylase synthesis by Bacillus amyloliquefaciens.

The purpose of this study was to investigate the effect of yeast extract on α-amylase synthesis by B. amyloliquefaciens F under controlled and uncontrolled pH conditions. In addition the by-product formation during fermentation and its influence on α-amylase is also reported
Thermal Radiation Properties of Propylene

Abstract The infrared absorption of hydrocarbons is important in the determination of the effect of thermal blockage on the ignition and combustion of condensed fuels. Low-resolution spectral absorptivity data for propylene in the region from 2 to 15 μ are presented for temperatures between 290 and 830 K and pressures between 0.05 and 2 atm. The data have been used in conjunction with the general statistical narrow-band model and Edwards' exponential wideband model to define the spectral absorption characteristics of the gas. The wide-band model is used to calculate the Planck mean absorption coefficient and total emissivity, which are presented in graphical form.
The Dangers of the New Sensibilities in Eighteenth Century German Acting

Playacting in public has been considered suspect since the day Solon stepped backstage to ask whether Thespis felt ashamed to tell so many lies to such a great number of people. From the very beginning, there were recognizable dangers not only for the audience but also for the actors themselves. And every possible attempt was made to point out those dangers and to obviate them. In the Republic, Plato warned against imitating anything except pure virtue. Especially dangerous, in his opinion, was the imitation of a woman, ‘old or young, railing against her husband, or boasting of a happiness which she imagines can rival the gods', or overwhelmed with grief and misfortune; much less a woman in love, or sick, or in labour.’ Plato, and a long line of writers who followed, condemned such imitation, contending that the imitator could all too easily become what he imitated. In the Ion, Plato discussed the divine frenzy that overcame the actor and made him momentarily insane or unable to distinguish truth from illusion.
The arrangement of F-actin and microtubules during germination of Mucor rouxii sporangiospores

The distribution of F-actin microfilaments and microtubules was analyzed in germinating sporangiospores of Mucor rouxii by labeling with rhodamine-tagged phalloidin and by immunofluorescence microscopy. The transition from isodiametrical to apical growth was accompanied by a switch from uniform distribution of F-actin patches to a polarized accumulation of F-actin material at the germ tube tips. Immunoblotting of cell-free extracts of M. rouxii with a monoclonal anti-porcine alpha-tubulin antibody (TU-01) disclosed two discrete bands of alpha-tubulin suggesting the existence of two alpha-tubulin genes in this fungus. Immunofluorescence microscopy of germinating cells stained with the same antibody revealed an elaborate network of cytoplasmic microtubules that persisted during the entire germination process and extended into the apex of the germ tube. Although their precise roles remain undetermined, the observed arrangement of cytoskeletal elements during germination is consistent with their presumed involvement in cell wall morphogenesis: the long axial microtubules serving as long-distance conveyors of wall-building vesicles to the apical region while the concentrated F-actin patches mark the participation of microfilaments in the zone of intense vesicle exocytosis at the hyphal apex.
Desorption rates of two PCB congeners from suspended sediments---II. model simulation

Abstract A two-compartment diffusion model has been developed and applied to simulate the desorption kinetics of two PCB congeners [2,5,2′,5′-tetrachlorobiphenyl (PCB-52) and 2,4,5,2′,4′,5′-hexachlorobiphenyl (PCB-153)] from suspended aquatic sediments (experimental results presented in the preceding paper). Simulation results suggest that (1) both non-equilibrium sorption and non-uniform particle size distribution of the natural sediments used in this study may have contributed to the observed two-distinct-rate desorption behavior of PCBs; and (2) that the two-compartment diffusion model, which assumes that one fraction of PCBs in solid phase reaches an instantaneous equilibrium with the surrounding aqueous phase while the other fraction follows intraparticle diffusion, fits the data far better than the single retarded pore diffusion model. Simulation results further suggest that increasing adsorption equilibration time (aging) will generally decrease the instantaneous equilibrium fraction and the effective pore diffusion coefficient.
The structural and functional aspects of hair cell regeneration in the chick as a result of exposure to intense sound

This paper summarizes the structural and functional damage caused by intense sound exposure in neonatal chicks. Scanning electron microscopy has been used to follow the structural changes to the papilla and their subsequent repair. Pure-tone exposures produced a localized lesion consisting of tectorial membrane destruction, changes in surface organization of the papilla, and hair cell loss. The papilla underwent significant repair following the exposure and new hair cells could be identified on the sensory surface after 4 days of recovery. In addition, various evoked-potential methods provided an objective assessment of auditory function and demonstrated that the peripheral ear was severely impaired by overstimulation. Auditory function returned to near normal levels within 3 days postexposure. The inescapable conclusion from these observations was that hair cell regeneration had little to do with the functional recovery observed during the first 3 days. Tectorial membrane regeneration and the restoration of cochlear micromechanics were combined to form a hypothesis to account for the restoration of auditory function.
Studies on the metabolism of amino acids and related compounds in vivo. IV. Blood ammonia and urea levels following intraperitoneal administration of amino acids and ammonium acetate, and the effect of arginine thereon.

Blood ammonia and urea levels were determined in rats which had been injected intraperitoneally (a) with LD99.9 ammonium acetate alone and with a prior injection of l-arginine. HCl, l-ornithine. HCl, or l-citrulline; (b) with LD99.9 levels of l- or d-amino acids; (c) with LD99.9 levels of l-amino acids together with l-arginine · HCl; and (d) with an LD99.9 level of a mixture of nine essential l-amino acids in the presence and absence of l-arginine. HCl. 1. (a). Injection of an LD99.9 dose of ammonium acetate was followed by a rapid rise in blood ammonia, a moderate increase in blood urea, and death of the animals; in the presence of protective levels of arginine, ornithine, or citrulline, the rise in blood ammonia was quickly checked and the values of this component rapidly fell to normal levels as the urea markedly increased, and the animals survived. 2. (b). Animals injected with LD99.9 levels of l- and d-amino acids died with elevated blood ammonia, and with elevated blood urea except for l-valine, and l- and d-histidine. HCl which evoked normal blood urea levels. 3. (c). Addition of l-arginine. HCl to each of the l-amino acids, resulted in survival of the threonine-injected rats, a drop in the blood ammonia levels of rats given isoleucine, leucine, threonine, lysine, and tryptophan, with no change in the blood ammonia levels of rats given methionine, valine, histidine. HCl, and phenylalanine; the blood urea levels in animals injected with isoleucine, leucine, threonine, and phenylalanine appreciably increased, whereas with the five other amino acids no change in urea levels was noted. 4. (d). Animals given the LD99.9 mixture of nine essential l-amino acids died with a moderately elevated blood ammonia and a slightly subnormal blood urea level. In the presence of a relatively low level of l-arginine. HCl the animals survived with a normal level of blood ammonia and an elevated urea level. In the presence of a much higher level of l-arginine. HCl, the animals died with elevated blood ammonia and urea levels, the innate toxic effect of so much arginine outweighing its ordinary protective effect.
The Last Interglaciation in Northeast Siberia

Alluvial, fluvial, and organic deposits of the last interglaciation are exposed along numerous river terraces in northeast Siberia. Although chronological control is often poor, the paleobotanical data suggest range extensions of up to 1000 km for the primary tree species. These data also indicate that boreal communities of the last interglaciation were similar to modern ones in composition, but their distributions were displaced significantly to the north-northwest. Inferences about climate of this period suggest that mean July temperatures were warmer by 4 to 8°C, and seasonal precipitation was slightly greater. Mean January temperatures may have been severely cooler than today (up to 12°C) along the Arctic coast, but similar or slightly warmer than present in other areas. The direction and magnitude of change in July temperatures agree with Atmospheric General Circulation Models, but the 126,000-year-B.P. model results also suggest trends opposite to the paleobotanical data, with simulated cooler winter temperatures and drier conditions than present during the climatic optimum.
Triphasic behavioral response of motor units to submaximal fatiguing exercise.

We have measured the firing rate and amplitude of 4551 motor unit action potentials (MUAPs) recorded with concentric needle electrodes from the brachial biceps muscles of 10 healthy young adults before, during, and after 45 minutes of intermittent isometric exercise at 20% of maximum voluntary contraction (MVC), using an automatic method for decomposition of electromyographic activity (ADEMG). During and after exercise, MUAPs derived from contractions of 30% MVC showed progressive increase in mean firing rate (P less than or equal to .01) and amplitude (P less than or equal to .05). The firing rate increase preceded the rise in mean amplitude, and was evident prior to the development of fatigue, defined as reduction of MVC. Analysis of individual potentials revealed that the increase in firing rate and in amplitude reflected different MUAP subpopulations. A short-term (less than 1 minute) reduction in MUAP firing rates (P less than or equal to .05) was also observed at the onset of each test contraction. These findings suggest that motor units exhibit a triphasic behavioral response to prolonged submaximal exercise: (1) short-term decline and stabilization of onset firing rates, followed by (2) gradual and progressive increase in firing rates and firing variability, and then by (3) recruitment of additional (larger) motor units. The (2) and (3) components presumably compensate for loss of force-generating capacity in the exercising muscle, and give rise jointly to the well-known increase in total surface EMG which accompanies muscle fatigue.
Distribution of choline acetyltransferase, acetylcholinesterase, muscarinic receptor binding, and choline uptake in discrete areas of the rat medulla oblongata.

Quantitative measurements were made of choline acetyltransferase (CAT) activity, acetylcholinesterase (AChE) acitivity and cholinergic muscarinic receptor binding ([3H]QNB) in eight areas of a cross-section of the rat medulla oblongata. A fourth cholinergic parameter, high-affinity choline uptake, was measured in three groups of these areas. CAT, AChE and [3H]QNB binding were found to be highest in the hypoglossal nucleus and the dorsal motor nucleus of the vagus; the lowest value was in the area which contains the inferior olive and the corticospinal tract. The distribution of AChE and CAT acitivities varied approximately 7- to 10-fold among the eight regions examined, whereas that of the muscarinic receptor varied only about 4-fold. The Na+-dependent high-affinity choline uptake varied approximately 20-fold from the region with the lowest activity (inferior olivary nucleus and corticospinal tract) to that with the highest activity (tissue areas containing the dorsal motor nucleus, hypoglossal nucleus, nucleus of the solitary tract and nucleus cuneatus). The four cholinergic parameters are statistically correlated throughout all the areas of the medulla which were studied.
Nucleus accumbens, thalamus and insula connectivity during incentive anticipation in typical adults and adolescents.

Reward neurocircuitry links motivation with complex behavioral responses. Studies of incentive processing have repeatedly demonstrated activation of nucleus accumbens (NAc), thalamus, and anterior insula, three key components of reward neurocircuitry. The contribution of the thalamus to this circuitry in humans has been relatively ignored, a gap that needs to be filled, given the central role of this structure in processing and filtering information. This study aimed to understand how these three regions function as a network during gain or loss anticipation in adults and youth. Towards this goal, functional magnetic resonance imaging (fMRI) and dynamic causal modeling (DCM) were used to examine effective connectivity among these three nodes in healthy adults and adolescents who performed the monetary incentive delay (MID) task. Seven connectivity models, based on anatomic connections, were tested. They were estimated for incentive anticipation and underwent Bayesian Model Selection (BMS) to determine the best-fit model for each adult and adolescent group. Connection strengths were extracted from the best-fit model and examined for significance in each group. These variables were then entered into a linear mixed model to test between-group effects on effective connectivity in reward neurocircuitry. The best-fit model for both groups included all possible anatomic connections. Three main findings emerged: (1) Across the task, thalamus and insula significantly influenced NAc; (2) A broader set of significant connections was found for the loss-cue condition than the gain-cue condition in both groups; (3) Finally, between-group comparisons of connectivity strength failed to detect statistical differences, suggesting that adults and adolescents use this incentive-processing network in a similar manner. This study demonstrates the way in which the thalamus and insula influence the NAc during incentive processing in humans. Specifically, this is the first study to demonstrate in humans the key role of thalamus projections onto the NAc in support of reward processing. Our results suggest that anticipation of gain/loss involves an ‘alerting’ signal (thalamus) that converges with interoceptive information (insula) to shape action selection programs in the ventral striatum.
Histologic predictors of survival in acquired immunodeficiency syndrome-associated Kaposi's sarcoma.

Abstract The relationship between 22 histologic variables and survival was investigated in 93 patients with acquired immunodeficiency syndrome (AIDS)-associated Kaposi's sarcoma (KS). All the patients were homosexual men in whom KS was the initial manifestation of AIDS. All patients were followed for at least 12 months or until death. Histologic specimens of the initial KS biopsy were reviewed in a blind manner by two of the authors and were evaluated for the presence of a number of histologic features. In a univariate analysis nodular lesions of KS ( v patch or plaque lesions), the absence of hemosiderin, the absence of irregular vascular spaces, and the presence of spindle cell nodules were all significantly associated with increased length of survival. Two variables previously shown to be related to survival (CD4:CD8 cell ratio, initial lesion on lower extremities) were included in a multivariate analysis (Cox model) in addition to the histologic variables. Complete data were avaiable from 85 patients. In the multivariate analysis a higher helper to suppressor T-cell ratio, initial lesion on lower extremities, presence of spindle cell nodules, and nodular histology ( v patch or plaque histology) were all significantly associated with increased length of survival. These data suggest that in AIDS-associated KS, as in reticuloendothelial neoplasms, histologic features may be useful in idenitifying prognostically different subgroups of patients.
Contract Costs and the Liability Structure for Stranger-Tenant Damages in Sierra Leone's Customary Land Law: An Economic Analysis

In the Sierra Leone Provinces, customary land law dictates that if an individual from another chiefdom or country wishes to rent land in a certain locality, he visits a landholder or head of an extended family and expresses a desire to be the landlord's stranger. If the landlord accepts the individual as his stranger, he becomes liable for any damages caused by the stranger to other natives' properties. This study applies some recent advances in welfare economics (see, for example, Coase, 1960; Demsetz, 1964, 1968) to pursue some interesting aspects of the landlord-stranger relationship. In particular, it is argued that within traditional society putting the liability for strangers' damages on the landlords' shoulders was efficient in a value-theoretic sense because landlords were more efficient than the government or the damaged parties in collecting damages from strangers and, therefore, that the magnitude of the collection cost would have been greater if the liability had been placed directly on the strangers. The paper also shows rigorously how and why it was that the higher the cost of collecting damages from tenants, the lower was the real income produced by the land. Therefore, if the government of the damaged parties should become lower-cost collectors, putting the liability directly on the strangers for any damage they cause would become the pareto-optimal arrangement.