This paper examines a number of the criticisms that citation analysis has been subjected to over the years. It is argued that many of these criticisms have been based on only limited examinations of data in particular contexts and it remains unclear how broadly applicable these problems are to research conducted at different levels of analysis, in specific fields, and among various national data sets. Relevant evidence is provided from analysis of Australian and international data. Citation analysis is likely to be most reliable when data is aggregated and at the highly-cited end of the distribution. It is possible to make valid inferences about individual cases, although considerable caution should be used. Bibliometric measures should be viewed as a useful supplement to other research evaluation measures rather than as a replacement.

To study the influence of genomic context on transgene expression, we have determined the T-DNA structure, flanking DNA sequences, and chromosomal location of four independent transgene loci in tobacco. Two of these loci were stably expressed in the homozygous condition over many generations, whereas the other two loci became unstable after several generations of homozygosity. The stably expressed loci comprised relatively simple T-DNA arrangements that were flanked on at least one side by plant DNA containing AT-rich regions that bind to nuclear matrices in vitro. Of the unstably expressed loci, one consisted of multiple incomplete T-DNA copies, and the second contained a single intact T-DNA; in both cases, however, binary vector sequences were directly contiguous to a right T-DNA border. Fluorescence in situ hybridiration demonstrated that the two stably expressed inserts were present in the vicinity of telomeres.The two unstably expressed inserts occupied intercalary and paracentromeric locations, respectively. Results on the stability of transgene expression in F, progeny obtained by intercrossing the four lines and the sensitivity of the four transgene loci to inactivation in the presence of an unlinked " frans-silencing" locus are also presented. The findings are discussed in the context of repetitive DNA sequences and the allotetraploid nature of the tobacco genome.

The interaction of chromatin with the nuclear matrix via matrix attachment regions (MARs) o n the DNA is considered to be of fundamental importance for higher order chromatin organization and regulation of gene expression. Here, we report a novel nuclear matrix-localized MAR DNA binding protein, designated MAR binding filament-like protein 1 (MFPl), from tomato. In contrast t o the few animal MAR DNA binding proteins thus far identified, MFPl contains a predicted N-terminal transmembrane domain and a long filament-like a-helical domain that is similar to diverse nuclear and cyto-plasmic filament proteins from animals and yeast. DNA binding assays established that MFPl can discriminate between animal and plant MAR DNAs and non-MAR DNA fragments of similar size and AT content. Deletion mutants of MFPl revealed a novel, discrete DNA binding domain near the C terminus of the protein. MFPl is an in vitro substrate for casein kinase II, a nuctear matrix-associated protein kinase. Its structure, MAR DNA binding activity, and nuclear matrix local-ization suggest that MFP1 is likely to participate in nuclear architecture by connecting chromatin with the nuclear matrix and potentially with the nuclear envelope.

No abstract

No abstract

The postwar trend in migration from central cities to the suburbs continues. In recent decades, this wave of migration has included increasing numbers of Asians, Hispanics, and blacks. The authors focus on the spatial overlap of race, ethnicity, and class in a large sample of suburban communities. Specifically, they examine differences in the characteristics of suburbs to which blacks, Hispanics, and Asians have gained residential access. By introducing controls for levels of community affluence, they address the controversial argument that levels of racially defined inequality diminish as the social class of members of minority groups increases.

Objectives Older nursing home residents make up the population at greatest risk of morbidity and mortality from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. No studies have examined the determinants of long-term antibody responses post vaccination in this group. Design Longitudinal cohort study. Setting and Participants Residents from 5 nursing homes assessed before vaccination, and 5 weeks and 6 months post vaccination, with the BNT162b2 messenger RNA SARS-CoV-2 vaccine. Methods Comprehensive clinical assessment was performed, including assessment for comorbidity, frailty, and SARS-CoV-2 infection history. Serum nucleocapsid and anti-spike receptor binding domain (RBD) antibodies were analyzed at all timepoints. An in vitro angiotensin-converting enzyme (ACE2) receptor-spike RBD neutralization assay assessed serum neutralization capacity. Results Of 86 participants (81.1 ± 10.8 years; 65% female), just under half (45.4%; 39 of 86) had evidence of previous SARS-CoV-2 infection. All participants demonstrated a significant antibody response to vaccination at 5 weeks and a significant decline in this response by 6 months. SARS-CoV-2 infection history was the strongest predictor of antibody titer (log-transformed) at both 5 weeks [β: 3.00; 95% confidence interval (CI): 2.32–3.70; P < .001] and 6 months (β: 3.59; 95% CI: 2.89–4.28; P < .001). Independent of SARS-CoV-2 infection history, both age in years (β: −0.05; 95% CI: −0.08 to −0.02; P < .001) and frailty (β: −0.22; 95% CI: −0.33 to −0.11; P < .001) were associated with a significantly lower antibody titer at 6 months. Anti-spike antibody titers at both 5 weeks and 6 months significantly correlated with in vitro neutralization capacity. Conclusions and Implications In older nursing home residents, SARS-CoV-2 infection history was the strongest predictor of anti-spike antibody titers at 6 months, whereas age and frailty were independently associated with lower titers at 6 months. Antibody titers significantly correlated with in vitro neutralization capacity. Although older SARS-CoV-2 naïve nursing home residents may be particularly vulnerable to breakthrough SARS-CoV-2 infection, the relationship between antibody titers, SARS-CoV-2 infection, and clinical outcomes remains to be fully elucidated in this vulnerable population.

The interaction of chromatin with the nuclear matrix via matrix attachment regions (MARs) o n the DNA is considered to be of fundamental importance for higher order chromatin organization and regulation of gene expression. Here, we report a novel nuclear matrix-localized MAR DNA binding protein, designated MAR binding filament-like protein 1 (MFPl), from tomato. In contrast t o the few animal MAR DNA binding proteins thus far identified, MFPl contains a predicted N-terminal transmembrane domain and a long filament-like a-helical domain that is similar to diverse nuclear and cytoplasmic filament proteins from animals and yeast. DNA binding assays established that MFPl can discriminate between animal and plant MAR DNAs and non-MAR DNA fragments of similar size and AT content. Deletion mutants of MFPl revealed a novel, discrete DNA binding domain near the C terminus of the protein. MFPl is an in vitro substrate for casein kinase II, a nuctear matrix-associated protein kinase. Its structure, MAR DNA binding activity, and nuclear matrix localization suggest that MFP1 is likely to participate in nuclear architecture by connecting chromatin with the nuclear matrix and potentially with the nuclear envelope.