Background: Oto-Acoustic Emissions (OAE) are low intensity sounds produced by the cochlea in response to an acoustic stimulus. Deliberate self-poisoning has become an increasingly common response to emotional distress...Background: Oto-Acoustic Emissions (OAE) are low intensity sounds produced by the cochlea in response to an acoustic stimulus. Deliberate self-poisoning has become an increasingly common response to emotional distress in young adults (NHS, 1998). Organophosphate (OP) compounds are most commonly involved in 76% of pesticide poisoning especially in the developing countries like India. Several pesticides are neurotoxin which could potentially affect hearing and, animal studies showed that OP treatment leads to change in hearing threshold, outer and inner hair cell loss but human studies on the same are very few. Aim: The present study was aimed at exploring the cochlear changes after self-poisoning with OP pesticides by measuring the Distortion Product Oto-Acoustic Emissions (DPOAE). Method: 114 subjects were participated in the study, with an age range of 18-30 years having pure tone audiometric thresholds within the normal limits and no history of middle ear pathology. They were further divided into two groups, I and II which includes self-poisoned and healthy subjects respectively. Results: The “pass” and “fail” criteria of DPOAE measures in group I were 30% and 70% respectively whereas in group II, it was found 91% and 9% respectively. Discussion: There was a significant failure in DPOAE in Group I (subjects who were self-poisoned) compared to group II (healthy subjects). The two important pathologies behind OP toxicity are the generation of Reactive Oxygen Species and the depletion of NADPH which is necessary for normal function. Conclusion: The results of the present study highlight that;the minute cochlear changes caused due to pesticide poisoning can be effectively measured through DPOAE. Further it can suggest in other clinical targets like Ototoxicity, Noise-induced hearing loss, Meniere’s disease etc., which has an effect on cochlear hair cells can be monitored through DPOAE.展开更多
The present work,based on lithostratigraphy and biostratigraphy,is focused on ammonites,microfacies,and chemostratigraphic study(δ^(13)C and δ^(18)O)of the late Cenomanian-early Turonian sequence in the El Bayadh ar...The present work,based on lithostratigraphy and biostratigraphy,is focused on ammonites,microfacies,and chemostratigraphic study(δ^(13)C and δ^(18)O)of the late Cenomanian-early Turonian sequence in the El Bayadh area(Saharan Atlas,Algeria).Five informal stratigraphic units(units 1 to 5)have been defined within the Rhoundjaia Formation,which is subdivided into four ammonite biozones:the Neolobites vibrayeanus,the Metoicoceras geslinianum,the Vascoceras cauvini,and the Choffaticeras sinaiticum zones.The Cenomanian-Turonian boundary(CTB)is located at the limit between units 2 and 3.Field data and microscopic analysis have resulted in the recognition of fourteen microfacies types(MT 1 to MT 14)that are described in terms of depositional environments,and grouped into six main limestone and limestone-marl facies associations(FA 1-6),representing two different palaeosettings:(i)open shelf/ramp-type carbonate platform and(ii)isolated carbonate platform.The sequence stratigraphic analysis revealed two third-order depositional sequences(DS1 and DS2)covering a period of about 2.8 million years.The depositional model for the uppermost Cenomanian shows the presence of a rudist-and microbial-rich isolated carbonate platform,away from terrigenous influence,and surrounded by deep-water open shelf facies.The comparison of the isotopic fluctuation profile with those of various marine sites in the Tethyan Ocean shows synchronous global events.展开更多
The palynological assemblages from two Albian-Cenomanian boundary sections in North Bulgaria are described. The samples analyzed yielded a diverse palynological content including dinoflagellate cysts and miospores. Ba...The palynological assemblages from two Albian-Cenomanian boundary sections in North Bulgaria are described. The samples analyzed yielded a diverse palynological content including dinoflagellate cysts and miospores. Based on dinocyst nutrient and productivity indices a phase of enhanced nutrient availability and high primary productivity is inferred for the latest Albian interval. The pronounced predominance of peridinioid dinocysts in this interval, namely O. verrucosum, O. scabrosum and especially P. infusorioides is considered to reflect eutrophic conditions. It coincides with the increased phosphorus mass accumulation occurring at the top part of the Upper Albian Dekov Formation. OAE ld is indicated in the Tolovitsa karst spring section, based on palynofacies dominated by high amounts of granular amorphous organic matter （AOM） related to anoxic environmental conditions. These sections serve as evidence suggesting a relationship between Cretaceous peridinioid cysts （including Palaeohystichphora infusorioides, Ovoidinium verrucosum, O. scabrosum） and anoxic/suboxic conditions and/or high primary productivity. The pollen spectrum inferred relatively stable vegetation patterns of surrounding continental areas during and after the AlbiardCenomanian boundary interval and the times of OAE ld formation. The hinterland vegetation integrated mainly pteridophyte spores and gymnosperms. The area was part of the Southern Laurasian floral province which was characterized by warm temperate to subtropical humid climate. Angiosperms were still minor part of this vegetation.展开更多
文摘Background: Oto-Acoustic Emissions (OAE) are low intensity sounds produced by the cochlea in response to an acoustic stimulus. Deliberate self-poisoning has become an increasingly common response to emotional distress in young adults (NHS, 1998). Organophosphate (OP) compounds are most commonly involved in 76% of pesticide poisoning especially in the developing countries like India. Several pesticides are neurotoxin which could potentially affect hearing and, animal studies showed that OP treatment leads to change in hearing threshold, outer and inner hair cell loss but human studies on the same are very few. Aim: The present study was aimed at exploring the cochlear changes after self-poisoning with OP pesticides by measuring the Distortion Product Oto-Acoustic Emissions (DPOAE). Method: 114 subjects were participated in the study, with an age range of 18-30 years having pure tone audiometric thresholds within the normal limits and no history of middle ear pathology. They were further divided into two groups, I and II which includes self-poisoned and healthy subjects respectively. Results: The “pass” and “fail” criteria of DPOAE measures in group I were 30% and 70% respectively whereas in group II, it was found 91% and 9% respectively. Discussion: There was a significant failure in DPOAE in Group I (subjects who were self-poisoned) compared to group II (healthy subjects). The two important pathologies behind OP toxicity are the generation of Reactive Oxygen Species and the depletion of NADPH which is necessary for normal function. Conclusion: The results of the present study highlight that;the minute cochlear changes caused due to pesticide poisoning can be effectively measured through DPOAE. Further it can suggest in other clinical targets like Ototoxicity, Noise-induced hearing loss, Meniere’s disease etc., which has an effect on cochlear hair cells can be monitored through DPOAE.
基金financed by the‘Rezerwa Dyrektora INoZ,University of Silesia in Katowice’for 2023by AGH-UST Grant no.16.16.140.315(MK)。
文摘The present work,based on lithostratigraphy and biostratigraphy,is focused on ammonites,microfacies,and chemostratigraphic study(δ^(13)C and δ^(18)O)of the late Cenomanian-early Turonian sequence in the El Bayadh area(Saharan Atlas,Algeria).Five informal stratigraphic units(units 1 to 5)have been defined within the Rhoundjaia Formation,which is subdivided into four ammonite biozones:the Neolobites vibrayeanus,the Metoicoceras geslinianum,the Vascoceras cauvini,and the Choffaticeras sinaiticum zones.The Cenomanian-Turonian boundary(CTB)is located at the limit between units 2 and 3.Field data and microscopic analysis have resulted in the recognition of fourteen microfacies types(MT 1 to MT 14)that are described in terms of depositional environments,and grouped into six main limestone and limestone-marl facies associations(FA 1-6),representing two different palaeosettings:(i)open shelf/ramp-type carbonate platform and(ii)isolated carbonate platform.The sequence stratigraphic analysis revealed two third-order depositional sequences(DS1 and DS2)covering a period of about 2.8 million years.The depositional model for the uppermost Cenomanian shows the presence of a rudist-and microbial-rich isolated carbonate platform,away from terrigenous influence,and surrounded by deep-water open shelf facies.The comparison of the isotopic fluctuation profile with those of various marine sites in the Tethyan Ocean shows synchronous global events.
基金carried out in the frame of the IGCP Project 609 "Climate-environmental deteriorations during greenhouse phases:Causes and consequences of short-term Cretaceous sea-level changes "
文摘The palynological assemblages from two Albian-Cenomanian boundary sections in North Bulgaria are described. The samples analyzed yielded a diverse palynological content including dinoflagellate cysts and miospores. Based on dinocyst nutrient and productivity indices a phase of enhanced nutrient availability and high primary productivity is inferred for the latest Albian interval. The pronounced predominance of peridinioid dinocysts in this interval, namely O. verrucosum, O. scabrosum and especially P. infusorioides is considered to reflect eutrophic conditions. It coincides with the increased phosphorus mass accumulation occurring at the top part of the Upper Albian Dekov Formation. OAE ld is indicated in the Tolovitsa karst spring section, based on palynofacies dominated by high amounts of granular amorphous organic matter （AOM） related to anoxic environmental conditions. These sections serve as evidence suggesting a relationship between Cretaceous peridinioid cysts （including Palaeohystichphora infusorioides, Ovoidinium verrucosum, O. scabrosum） and anoxic/suboxic conditions and/or high primary productivity. The pollen spectrum inferred relatively stable vegetation patterns of surrounding continental areas during and after the AlbiardCenomanian boundary interval and the times of OAE ld formation. The hinterland vegetation integrated mainly pteridophyte spores and gymnosperms. The area was part of the Southern Laurasian floral province which was characterized by warm temperate to subtropical humid climate. Angiosperms were still minor part of this vegetation.
