Learning During a Crisis: the SARS Epidemic in Taiwan

When SARS struck Taiwan in the spring of 2003, many people feared that the disease would spread through the healthcare system. As a result, outpatient medical visits fell by over 30 percent in the course of a few weeks. This paper examines how both public information (SARS incidence reports) and private information (the behavior and opinions of peers) contributed to this public reaction. We identify social learning through a difference-in-difference strategy that compares long time community residents to recent arrivals, who are less socially connected. We find that people learned from both public and private sources during SARS. In a dynamic simulation based on the regressions, social learning substantially magnifes the response to SARS.

Media Bias and Influence: Evidence from Newspaper Endorsements

This paper investigates the relationship between media bias and the influence of the media on voting in the context of newspaper endorsements. We first develop a simple econometric model in which voters choose candidates under uncertainty and rely on endorsements from better informed sources. Newspapers are potentially biased in favor of one of the candidates and voters thus rationally account for the credibility of any endorsements. Our primary empirical finding is that endorsements are influential in the sense that voters are more likely to support the recommended candidate after publication of the endorsement. The degree of this influence, however, depends upon the credibility of the endorsement. In this way, endorsements for the Democratic candidate from left-leaning newspapers are less influential than are endorsements from neutral or right-leaning newspapers, and likewise for endorsements for the Republican. These findings suggest that voters do rely on the media for information during campaigns but that the extent of this reliance depends upon the degree and direction of any bias.

Crystallization of Adenylylsulfate Reductase from Desulfovibrio gigas: A Strategy Based on Controlled Protein Oligomerization

Adenylylsulfate reductase (adenosine 5′-phosphosulfate reductase, APS reductase or APSR, E.C.1.8.99.2) catalyzes the conversion of APS to sulfite in dissimilatory sulfate reduction. APSR was isolated and purified directly from massive anaerobically grown Desulfovibrio gigas, a strict anaerobe, for structure and function investigation. Oligomerization of APSR to form dimers–α_2β_2, tetramers–α_4β_4, hexamers–α_6β_6, and larger oligomers was observed during purification of the protein. Dynamic light scattering and ultracentrifugation revealed that the addition of adenosine monophosphate (AMP) or adenosine 5′-phosphosulfate (APS) disrupts the oligomerization, indicating that AMP or APS binding to the APSR dissociates the inactive hexamers into functional dimers. Treatment of APSR with β-mercaptoethanol decreased the enzyme size from a hexamer to a dimer, probably by disrupting the disulfide Cys156—Cys162 toward the C-terminus of the β-subunit. Alignment of the APSR sequences from D. gigas and A. fulgidus revealed the largest differences in this region of the β-subunit, with the D. gigas APSR containing 16 additional amino acids with the Cys156—Cys162 disulfide. Studies in a pH gradient showed that the diameter of the APSR decreased progressively with acidic pH. To crystallize the APSR for structure determination, we optimized conditions to generate a homogeneous and stable form of APSR by combining dynamic light scattering, ultracentrifugation, and electron paramagnetic resonance methods to analyze the various oligomeric states of the enzyme in varied environments

Square Key Matrix Management Scheme in Wireless Sensor Networks

In this paper we propose a symmetric cryptographic approach named Square Key Matrix Management Scheme (SKMaS) in which a sensor node named Key Distribution Server (KDS) is responsible for the security of key management. When the system starts up, the KDS sends its individual key and two sets of keys to sensor nodes. With the IDs, any two valid sensor nodes, e.g. i and j, can individually identify the corresponding communication keys (CKs) to derive a dynamic shared key (DSK) for encrypting/decrypting messages transmitted between them. When i leaves the underlying network, the CKs and the individually keys currently utilized by i can be reused by a newly joining sensor, e.g. h. However, when h joins the network, if no such previously-used IDs are available, h will be given a new ID, CKs and the individually key by the KDS. The KDS encrypts the CKs, with which an existing node q can communicate with h, with individual key so that only q rather than h can correctly decrypt the CKs. The lemmas and security analyses provided in this paper prove that the proposed system can protect at least three common attacks

Applying a Comprehensive Action Determination Model to Examine the Recycling Behavior of Taipei City Residents

With the occurrence of rapid global economic growth concerns about waste and its related effects on the environment are on the rise. There has been an increasing focus towards sustainable development and waste recycling as part of environmental sustainability strategies, and the encouraging of recycling behavior has received considerable attention from various environmental stakeholders. While numerous studies have used grounded theories such as the theory of planned behaviors and the norm activation model to examine environmental behaviors, a lack of consideration of other important variables in these studies has been revealed. This study aimed to address this gap by adopting the comprehensive action determination model, which comprises a wider group of influencing variables related to norms, intentions, situations, and habits. This model was tested using structural equation modelling with a sample of 386 valid questionnaires collected from Taipei City residents in the domain of recycling behaviors. Results indicated that awareness had a positive influence on personal norms towards recycling behaviors; social norms had a positive influence on personal norms towards recycling behaviors; attitudes had a positive influence on recycling intentions; social norms had a positive influence on recycling intentions; personal norms had a positive influence on recycling intentions; perceived behavior control had a positive influence on recycling intentions; recycling intentions had a positive influence on recycling behavior; and recycling habits had a positive influence on recycling behavior. However, findings did not support the positive impact of perceived behavioral control on recycling behavior

Antitumor agents. 258. Syntheses and evaluation of dietary antioxidant—taxoid conjugates as novel cytotoxic agents

Various dietary antioxidants, including vitamins, flavonoids, curcumin, and a coumarin, were conjugated with paclitaxel (1) through an ester linkage. The newly synthesized compounds were evaluated for cytotoxic activity against several human tumor cell lines as well as the corresponding normal cell lines. Interestingly, most tested conjugates selectively inhibited the growth of 1A9 (ovarian) and KB (nasopharyngeal) tumor cells without activity against other cell lines. Particularly, conjugates 16 and 20 were highly active against 1A9 (ED50 value of 0.005 μg/mL) as well as KB (ED50 values of 0.005 and 0.14 μg/mL, respectively) cells. Compound 22b, the glycinate ester salt of vitamin E conjugated with 1, appears to be a promising lead for further development as a clinical trial candidate as it exhibited strong inhibitory activity against Panc-1 (pancreatic cancer) with less effect on the related E6E7 (normal) cell line

Introgression Between Cultivars and Wild Populations of Momordica charantia L. (Cucurbitaceae) in Taiwan

The landrace strains of Momordica charantia are widely cultivated vegetables throughout the tropics and subtropics, but not in Taiwan, a continental island in Southeast Asia, until a few hundred years ago. In contrast, the related wild populations with smaller fruit sizes are native to Taiwan. Because of the introduction of cultivars for agricultural purposes, these two accessions currently exhibit a sympatric or parapatric distribution in Taiwan. In this study, the cultivars and wild samples from Taiwan, India, and Korea were collected for testing of their hybridization and evolutionary patterns. The cpDNA marker showed a clear distinction between accessions of cultivars and wild populations of Taiwan and a long divergence time. In contrast, an analysis of eight selectively neutral nuclear microsatellite loci did not reveal a difference between the genetic structures of these two accessions. A relatively short divergence time and frequent but asymmetric gene flows were estimated based on the isolation-with-migration model. Historical and current introgression from cultivars to wild populations of Taiwan was also inferred using MIGRATE-n and BayesAss analyses. Our results showed that these two accessions shared abundant common ancestral polymorphisms, and the timing of the divergence and colonization of the Taiwanese wild populations is consistent with the geohistory of the Taiwan Strait land bridge of the Last Glacial Maximum (LGM). Long-term and recurrent introgression between accessions indicated the asymmetric capacity to receive foreign genes from other accessions. The modern introduction of cultivars of M. charantia during the colonization of Taiwan by the Han Chinese ethnic group enhanced the rate of gene replacement in the native populations and resulted in the loss of native genes

Mixed Infections of Helicobacter pylori

Background. Persistent Helicobacter pylori infection may induce several upper gastrointestinal diseases. Two major virulence factors of H. pylori, vacuolating cytotoxin A (VacA) and cytotoxin-associated gene A (CagA), are thought to be associated with the severity of disease progression. The distribution of vacA and cag-pathogenicity island (cag-PAI) alleles varies in H. pylori isolated from patients in different geographic regions. Aim. To assess the association between mixed infection of H. pylori clinical isolates from Taiwanese patients and the severity of gastrointestinal diseases. Methods. A total of 70 patients were enrolled in this study. Six distinct and well-separated colonies were isolated from each patient and 420 colonies were analyzed to determine the genotypes of virulence genes. Results. The prevalence of mixed infections of all H. pylori-infected patients was 28.6% (20/70). The rate of mixed infections in patients with duodenal ulcer (47.6%) was much higher than that with other gastrointestinal diseases (P<0.05). Conclusions. H. pylori mixed infections show high genetic diversity that may enhance bacterial adaptation to the hostile environment of the stomach and contribute to disease development

Detection of SARS-associated Coronavirus in Throat Wash and Saliva in Early Diagnosis

Early detection of SARS-CoV in throat wash and saliva suggests that these specimens are ideal for SARS diagnosis

Clinical characteristics and prognosis of acute bacterial meningitis in elderly patients over 65: a hospital-based study

<p>Abstract</p> <p>Background</p> <p>To examine the clinical characteristics of bacterial meningitis in elderly patients.</p> <p>Methods</p> <p>261 patients with adult bacterial meningitis (ABM), collected during a study period of 11 years (2000-2010), were included for study. Among them, 87 patients aged ≥ 65 years and were classified as the elderly group. The clinical and laboratory characteristics and prognostic factors were analyzed, and a clinical comparison with those of non-elderly ABM patients was also made.</p> <p>Results</p> <p>The 87 elderly ABM patients were composed of 53 males and 34 females, aged 65-87 years old (median = 71 years). Diabetes mellitus (DM) was the most common underlying condition (34%), followed by end stage renal disease (7%), alcoholism (4%) and malignancies (4%). Fever was the most common clinical manifestation (86%), followed by altered consciousness (62%), leukocytosis (53%), hydrocephalus (38%), seizure (30%), bacteremia (21%) and shock (11%). Thirty-nine of these 87 elderly ABM patients had spontaneous infection, while the other 48 had post-neurosurgical infection. Forty-four patients contracted ABM in a community-acquired state, while the other 43, a nosocomial state. The therapeutic results of the 87 elderly ABM patients were that 34 patients expired and 53 patients survived. The comparative results of the clinical and laboratory characteristics between the elderly and non-elderly ABM patients showed that only peripheral blood leukocytosis was significant. Presence of shock and seizure were significant prognostic factors of elderly ABM patients.</p> <p>Conclusions</p> <p>Elderly ABM patients accounted for 34.8% of the overall ABM cases, and this relatively high incidence rate may signify the future burden of ABM in the elderly population in Taiwan. The relative frequency of implicated pathogens of elderly ABM is similar to that of non-elderly ABM. Compared with non-elderly patients, the elderly ABM patients have a significantly lower incidence of peripheral blood leukocytosis. The mortality rate of elderly ABM remains high, and the presence of shock and seizures are important prognostic factors.</p