31 research outputs found
Fragments of mind: a thesis on the subject of experience, the structure of consciousness, and split-brain patients
Neuropsychological research on so-called split-brain patientsâindividuals whose corpus callosum has been severed as a treatment for severe epilepsyâhas revealed the possibility of startling breakdowns in the transmission of sensory information between the cerebral hemispheres. These experimental results have often been interpreted as demonstrating that split-brain patients have two streams of consciousness. In opposition to such views, this thesis argues for a conception of split-brain patients as having a single stream of consciousness thatâs disunified in highly specific experimental settings but unified outside of those settings. It is also argued that conceptions of split-brain patients as having two unified streams of consciousness and conceptions according to which they have one consistently unified stream of consciousness rely on a mistaken assumption: That a set of experiences belong to a stream of consciousness if and only if all the contemporaneous experiences in the stream are unified with each other
Pulmonary Epithelial Integrity in Children: Relationship to Ambient Ozone Exposure and Swimming Pool Attendance
Airway irritants such as ozone are known to impair lung function and induce airway inflammation. Clara cell protein (CC16) is a small anti-inflammatory protein secreted by the nonciliated bronchiolar Clara cells. CC16 in serum has been proposed as a noninvasive and sensitive marker of lung epithelial injury. In this study, we used lung function and serum CC16 concentration to examine the pulmonary responses to ambient O(3) exposure and swimming pool attendance. The measurements were made on 57 children 10â11 years of age before and after outdoor exercise for 2 hr. Individual O(3) exposure was estimated as the total exposure dose between 0700 hr until the second blood sample was obtained (mean O(3) concentration/m(3) Ă hours). The maximal 1-hr value was 118 ÎŒg/m(3) (59 ppb), and the individual exposure dose ranged between 352 and 914 ÎŒg/m(3)hr. These O(3) levels did not cause any significant changes in mean serum CC16 concentrations before or after outdoor exercise, nor was any decrease in lung function detected. However, children who regularly visited chlorinated indoor swimming pools had significantly lower CC16 levels in serum than did nonswimming children both before and after exercise (respectively, 57 ± 2.4 and 53 ± 1.7 ÎŒg/L vs. 8.2 ± 2.8 and 8.0 ± 2.6 ÎŒg/L; p < 0.002). These results indicate that repeated exposure to chlorination by-products in the air of indoor swimming pools has adverse effects on the Clara cell function in children. A possible relation between such damage to Clara cells and pulmonary morbidity (e.g., asthma) should be further investigated
The Nordic Expert Group for Criteria Documentation of Health Risks from Chemicals : 131. Lithium and lithium compounds
Lithium is a light soft metal. It reacts with water to form lithium hydroxide, but less vigorously than sodium. All lithium compounds are monovalent. In industry lithium and compounds are used e.g. in the manufacture of aluminium, as a flux in glass, enamel and ceramic industries, for manufacturing of lubricants, as a drying agent, as a reducing agent in organic synthesis, and in batteries. Industrial exposure to lithium and alkaline lithium compounds may give rise to irritation of the respiratory tract, eyes and skin or even corrosive lesions. For lithium hydride no irritant effects were seen below 0.025 mg LiH/m3, whereas at higher levels a tickling sensation in the nose was reported along with nasal discharge. At levels above 0.1 mg LiH/m3 a definite nasal irritation and coughing was experienced. Upper respiratory symptoms and skin irritation at exposure to approximately 0.02-0.05 mg Li/m3 in total dust, as LiOH, has also been reported. No other effects than irritation and corrosive effects have been clearly attributed to occupational exposure to lithium and compounds. However, some lithium compounds are used as drugs in the treatment of affective disorders. Adverse effects of lithium may occur in patients at therapeutic doses. At 12-hours serum lithium concentrations of 0.5-0.8 mM some of the most common side effects are nephrogenic diabetes insipidus, fine hand tremor, weight gain, increased thyroidstimulating hormone values and hypothyreosis. Available data indicate very low serum lithium levels in exposed workers, compared to patients receiving lithium drugs.Litium Ă€r en lĂ€tt, mjuk metall. Ămnet reagerar med vatten under bildning av litiumhydroxid, men reaktionen sker mindre hĂ€ftigt Ă€n för natrium. Alla litiumföreningar Ă€r envĂ€rda. Litium med föreningar anvĂ€nds industriellt, t ex vid tillverkning av aluminium, som flussmedel inom glas-, emalj- och keramisk industri, vid tillverkning av smörjmedel, som torkmedel, som reduktionsmedel i organisk syntes och i batterier. Litium och alkaliska litiumföreningar kan vid industriell exponering förorsaka irritation av luftvĂ€gar, ögon och hud eller t o m frĂ€tskador. För litiumhydrid har inga irritationseffekter rapporterats vid lufthalter under 0,025 mg LiH/m3, medan kittlingar i nĂ€san och snuva noterats vid högre nivĂ„er. Vid nivĂ„er över 0,1 mg LiH/m3 har klar nĂ€sirritation och hosta rapporterats. Symptom frĂ„n övre luftvĂ€garna och hudirritation har ocksĂ„ rapporterats vid exponering för ca 0,02-0,05 mg Li/m3 som litiumhydroxid (i totaldamm). Inga andra effekter Ă€n irritation och frĂ€tskador har kunnat tillskrivas litium och dess föreningar vid yrkesmĂ€ssig exponering. NĂ„gra litiumföreningar anvĂ€nds dock som lĂ€kemedel inom psykiatrin och biverkningar kan upptrĂ€da hos patienter vid terapeutiska doser. NĂ„gra av de vanligaste biverkningarna vid 12-timmarsvĂ€rdet 0,5-0,8 mM för serumlitium Ă€r nefrogen diabetes insipidus, finvĂ„gig handtremor, viktökning, förhöjda vĂ€rden pĂ„ tyroideastimulerande hormon och hypotyreos. TillgĂ€ngliga data indikerar att serumnivĂ„erna av litium hos exponerade arbetare Ă€r mycket lĂ„ga, jĂ€mfört med de nivĂ„er som uppmĂ€tts hos patienter. Nyckelord: hygieniskt grĂ€nsvĂ€rde, hĂ€lsoeffekter, irritation, litium, litiumhydrid, litiumhydroxid, riskbedömning, toxicitet, ögonskada, översikt
Systemic effects of occupational exposure to arsenic : with special reference to peripheral circulation and nerve function
Smelter workers who were exposed to air-borne arsenic for a mean of 23 years, and age-matched referents, were examined with clinical, physiological, and neurophysiological methods. Exposure to arsenic in workroom air was estimated to have been around the Swedish occupational limits, which were 500 yg/m before 1975 and 50 yg/ra thereafter. An increased preval ence of Raynaud's phenomenon and a reduced finger systolic blood pressure (FSP) during local and general cooling were found in the smelter workers. Slight, but significant sub-clinical neuropathy, in the form of slightly reduced nerve conduction velocity (NCV) in two or more peripheral nerves, was more common among the arsenic workers than among the referents. There were positive correlations between cumulative exposure to arsenic, reduced NCV in three peripheral motor nerves, and decrease in FSP during cooling. Arsenic levels in urine were 1 ymole/1 (75 yg/1) in the arsenic workers and 0.1 ymole/1 in the referents. In 21 arsenic workers with no or very low exposure to vibra ting hand tools, the FSP during cooling had increased significantly after 3 years wit h the lower arsenic exposure. There was no change in FSP during the summer vacation, whereas urinary levels of arsenic decreased to normal values. Thus there seems to be a slow improvement of finger blood circ ulation which is independent of short-term fluctuations in the exposure to arsenic. No seasonal variation was found in FSP during cooling with the standardized method used. When the NCV-measurements were repeated five years later the difference between arsenic workers and referents had increased, despite the fact that 14 of the 47 arsenic workers had had no exposure to arsenic during the last 1-5 years. These observations indicate, that in subjects with long term exposure to arsenic, sub-clinical neuropathy is not reversible. Ten milligrams of Ketanserin, a serotonin receptor antagonist, was given intravenously to five arsenic workers with cold-induced vasospasm. Skin temperature and FSP during cooling increased significantly with Ketanserin as compared wit h saline solution. After oral treatment, 2 x 40 mg /day for four weeks, no significant increase of FSP during cooling or rise in skin temperature was found in six arsenic workers and eleven patients with Raynaud's phenomenon. The decrease of vasospastic tendency after intravenous injection of Ketanserin indicated that similar mechanisms might operate in arsenic-induced and other types of Raynaud's phenomenon. A general co nclusion from the five studies in this dissertation is that long-term occupational exposure to arsenic has had adverse effects on the peripheral circulation and nerve conduction. The tendency to vasospasm, but not the sub-clinical neuropathy, seemed to be reversible with decreasing exposure.S. 1-54: sammanfattning, s. 55-112: 5 uppsatserdigitalisering@um
Systemic effects of occupational exposure to arsenic : with special reference to peripheral circulation and nerve function
Smelter workers who were exposed to air-borne arsenic for a mean of 23 years, and age-matched referents, were examined with clinical, physiological, and neurophysiological methods. Exposure to arsenic in workroom air was estimated to have been around the Swedish occupational limits, which were 500 yg/m before 1975 and 50 yg/ra thereafter. An increased preval ence of Raynaud's phenomenon and a reduced finger systolic blood pressure (FSP) during local and general cooling were found in the smelter workers. Slight, but significant sub-clinical neuropathy, in the form of slightly reduced nerve conduction velocity (NCV) in two or more peripheral nerves, was more common among the arsenic workers than among the referents. There were positive correlations between cumulative exposure to arsenic, reduced NCV in three peripheral motor nerves, and decrease in FSP during cooling. Arsenic levels in urine were 1 ymole/1 (75 yg/1) in the arsenic workers and 0.1 ymole/1 in the referents. In 21 arsenic workers with no or very low exposure to vibra ting hand tools, the FSP during cooling had increased significantly after 3 years wit h the lower arsenic exposure. There was no change in FSP during the summer vacation, whereas urinary levels of arsenic decreased to normal values. Thus there seems to be a slow improvement of finger blood circ ulation which is independent of short-term fluctuations in the exposure to arsenic. No seasonal variation was found in FSP during cooling with the standardized method used. When the NCV-measurements were repeated five years later the difference between arsenic workers and referents had increased, despite the fact that 14 of the 47 arsenic workers had had no exposure to arsenic during the last 1-5 years. These observations indicate, that in subjects with long term exposure to arsenic, sub-clinical neuropathy is not reversible. Ten milligrams of Ketanserin, a serotonin receptor antagonist, was given intravenously to five arsenic workers with cold-induced vasospasm. Skin temperature and FSP during cooling increased significantly with Ketanserin as compared wit h saline solution. After oral treatment, 2 x 40 mg /day for four weeks, no significant increase of FSP during cooling or rise in skin temperature was found in six arsenic workers and eleven patients with Raynaud's phenomenon. The decrease of vasospastic tendency after intravenous injection of Ketanserin indicated that similar mechanisms might operate in arsenic-induced and other types of Raynaud's phenomenon. A general co nclusion from the five studies in this dissertation is that long-term occupational exposure to arsenic has had adverse effects on the peripheral circulation and nerve conduction. The tendency to vasospasm, but not the sub-clinical neuropathy, seemed to be reversible with decreasing exposure.S. 1-54: sammanfattning, s. 55-112: 5 uppsatserdigitalisering@um
How Can Embedded Criminologists, Police Pracademics, and Crime Analysts Help Increase Police-Led Program Evaluations? A Survey of Authors Cited in the Evidence-Based Policing Matrix
Evidence-based policing emphasizes the evaluation of interventions to create a catalog of effective programs and practices. Program evaluation has primarily been considered the purview of academic researchers, with police agencies typically uninvolved in the evaluation of their own interventions. Scholars have recently advocated for police to take more ownership over program evaluation, often arguing for an increased role of three primary entities: embedded criminologists, police pracademics, and crime analysts. While an emerging body of literature has explored these entities individually, research has yet to explore the unique contributions each can make to police-led science. The current study is a survey of scholars who authored or co-authored one or more studies included in the Evidence-Based Policing Matrix. The authors explore four distinct research questions pertaining to police-led science. Findings suggest that embedded criminologists, police pracademics, and crime analysts may each have a unique role to play in promoting police-led science