Variability in captan residues in apples from a Canadian orchard

Apple trees in an orchard in Quebec, Canada were treated, following label directions, with the fungicide captan (1,2,3,6-tetrahydro-N-(trichloromethylthio)phthalimide) during the 2003 agricultural season. A total of 142 apples from three rows of trees were selected for determination of captan by GC/MS. Individual apples were found to contain captan levels ranging from 16.9 to 6350 ng g^-1. Only two individual apple samples exceeded the Canadian maximum residue limit (5000 ng g^-1) for captan in apples. Six composite samples, comprising half portions of eight individual apples, were analysed from each of the three experimental rows. Composite samples ranged in concentration from 166 to 2620 ng g^-1. The greatest uncertainty associated with the measured concentrations was due to variability among apples rather than the measurement of residue levels.     

Emerging and re-emerging infectious diseases: a biological evolutionary drama

Cervical intraepithelial neoplasia grade 3 (CIN 3) is treated surgically. Follow-up of these patients is important to ensure successful treatment. The present study was undertaken to determine whether human papillomavirus (HPV) testing can be used to discriminate patients who will have recurrences from those who will not. It is composed of 26 patients who presented with recurrences of CIN and 22 patients who remained disease-free after treatment. DNA was extracted from paraffin-embedded cone biopsies of incident CIN 3, their corresponding follow-up Pap smears taken 3 months postoperatively, and their secondary cone biopsies of the recurrent lesions. The extracted DNA were then analyzed by PCR for the presence of HPV. The posttreatment cervical smears in the recurrent group had a (25/26) 96% HPV prevalence, while HPV DNA was not detectable in any of the 22 patients in the control group. The HPV types in both the initial and recurrent lesions correlated very well. This suggest that most recurrences are likely to be due to persisting lesions or subclinical HPV infections that had not been completely removed. Cytology alone was not sufficiently sensitive to discriminate the patients at risk for recurrences. It appears that HPV testing can be useful to monitor the therapeutic result.     

Digital ischemia and gangrene due to red blood cell aggregation induced by acquired dysfibrinogenemia

Digital gangrene was observed in a patient who had angiographic findings of digital arterial occlusion. The patient's blood showed a marked red blood cell aggregation with rouleaux formation in long chains, which could not be dispersed at shear rates up to 200 sec-1. Studies of the patient's blood revealed the presence of an abnormal fibrinogen capable of aggregating normal red blood cells. This fibrinogen was found by Raman spectroscopy to have an increased alpha-helical content, whereas the beta-sheet content was decreased. Defibrinogenation therapy with ancrod resulted in a dramatic symptomatic relief. The disappearance of the abnormal fibrinogen 6 months later and an absence of a family history indicate that this dysfibrinogenemia was acquired.     

Recent advances in insect olfaction, specifically regarding the morphology and sensory physiology of antennal sensilla of the female sphinx moth Manduca sexta.

The antennal flagellum of female Manduca sexta bears eight sensillum types: two trichoid, two basiconic, one auriculate, two coeloconic, and one styliform complex sensilla. The first type of trichoid sensillum averages 34 microm in length and is innervated by two sensory cells. The second type averages 26 microm in length and is innervated by either one or three sensory cells. The first type of basiconic sensillum averages 22 microm in length, while the second type averages 15 microm in length. Both types are innervated by three bipolar sensory cells. The auriculate sensillum averages 4 microm in length and is innervated by two bipolar sensory cells. The coeloconic type-A and type-B both average 2 microm in length. The former type is innervated by five bipolar sensory cells, while the latter type, by three bipolar sensory cells. The styliform complex sensillum occurs singly on each annulus and averages 38-40 microm in length. It is formed by several contiguous sensilla. Each unit is innervated by three bipolar sensory cells. A total of 2,216 sensilla were found on a single annulus (annulus 21) of the flagellum. Electrophysiological responses from type-A trichoid sensilla to a large panel of volatile odorants revealed three different subsets of olfactory receptor cells (ORCs). Two subsets responded strongly to only a narrow range of odorants, while the third responded strongly to a broad range of odorants. Anterograde labeling of ORCs from type-A trichoid sensilla revealed that their axons projected mainly to two large female glomeruli of the antennal lobe.     

A methodology for the determination of code equivalency with respect to the provision of means of escape

The escape potential of occupants in a building and the effectiveness of existing escape strategies can be described as a function of the time required for escape and the time available for escape.

The formalisation of these two concepts within the contextual framework of equivalency is addressed in this paper. Existing fire simulation and people evacuation models (ASET and EVACNET+, respectively) are used to assess equivalent fire safety provision in public assembly buildings.

In each of the examples chosen, a safety index is derived for deemed-to-satisfy designs and used as a benchmark against which other prototype designs may be compared for the purpose of establishing code equivalency.

A methodology that is capable of assisting in the determination of code equivalency with respect to escape route provision while accommodating trade-off is postulated.