30 research outputs found

    Will intensity of forest regeneration measures improve volume production and economy?

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    The prevailing regeneration methods in Scandinavian countries are artificial regeneration methods including measures such as site preparation and planting. These measures are considered to be a part of a more intensive forest management and require an initial investment. The use of artificial regeneration measures can, however, increase the growth of a forest stand. In this study, the purpose was to investigate if such an investment is profitable by comparing three different intensity levels (low, medium and high) applied during the regeneration phase, with aspect on both economics (LEV, land expectation value) and growth (MAI, mean annual increment) after a full rotation. The forest stands used in this study were regenerated between 1984 and 1988 and the future growth of the stands was simulated using Heureka StandWise. It was clear that naturally regenerated (low intensity) stands resulted in better economics than stands actively regenerated (medium and high intensity). However, actively regenerated stands resulted in both higher volume production and growth, and the uncertainty of regeneration success was reduced using artificial regeneration measures. These factors are important when considering both the ongoing mitigation of carbon dioxide in the atmosphere and future access to raw material

    Rickettsia helvetica in Patient with Meningitis, Sweden, 2006

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    Pathogenicity of Rickettsia helvetica is relatively unknown. We isolated a spotted fever group rickettsial organism from a patient with subacute meningitis. Nucleotide sequences of the 16S rRNA, ompB, and 17kDa genes identified the isolate as R. helvetica. This organism may be associated with serious infections such as central nervous system disorders

    High Effective Coverage of Vector Control Interventions in Children After Achieving Low Malaria Transmission in Zanzibar, Tanzania.

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    \ud \ud Formerly a high malaria transmission area, Zanzibar is now targeting malaria elimination. A major challenge is to avoid resurgence of malaria, the success of which includes maintaining high effective coverage of vector control interventions such as bed nets and indoor residual spraying (IRS). In this study, caretakers' continued use of preventive measures for their children is evaluated, following a sharp reduction in malaria transmission. A cross-sectional community-based survey was conducted in June 2009 in North A and Micheweni districts in Zanzibar. Households were randomly selected using two-stage cluster sampling. Interviews were conducted with 560 caretakers of under-five-year old children, who were asked about perceptions on the malaria situation, vector control, household assets, and intention for continued use of vector control as malaria burden further decreases. Effective coverage of vector control interventions for under-five children remains high, although most caretakers (65%; 363/560) did not perceive malaria as presently being a major health issue. Seventy percent (447/643) of the under-five children slept under a long-lasting insecticidal net (LLIN) and 94% (607/643) were living in houses targeted with IRS. In total, 98% (628/643) of the children were covered by at least one of the vector control interventions. Seasonal bed-net use for children was reported by 25% (125/508) of caretakers of children who used bed nets. A high proportion of caretakers (95%; 500/524) stated that they intended to continue using preventive measures for their under-five children as malaria burden further reduces. Malaria risk perceptions and different perceptions of vector control were not found to be significantly associated with LLIN effective coverage While the majority of caretakers felt that malaria had been reduced in Zanzibar, effective coverage of vector control interventions remained high. Caretakers appreciated the interventions and recognized the value of sustaining their use. Thus, sustaining high effective coverage of vector control interventions, which is crucial for reaching malaria elimination in Zanzibar, can be achieved by maintaining effective delivery of these interventions

    Dissemination of Spotted Fever Rickettsia Agents in Europe by Migrating Birds

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    Migratory birds are known to play a role as long-distance vectors for many microorganisms. To investigate whether this is true of rickettsial agents as well, we characterized tick infestation and gathered ticks from 13,260 migratory passerine birds in Sweden. A total of 1127 Ixodes spp. ticks were removed from these birds and the extracted DNA from 957 of them was available for analyses. The DNA was assayed for detection of Rickettsia spp. using real-time PCR, followed by DNA sequencing for species identification. Rickettsia spp. organisms were detected in 108 (11.3%) of the ticks. Rickettsia helvetica, a spotted fever rickettsia associated with human infections, was predominant among the PCR-positive samples. In 9 (0.8%) of the ticks, the partial sequences of 17kDa and ompB genes showed the greatest similarity to Rickettsia monacensis, an etiologic agent of Mediterranean spotted fever-like illness, previously described in southern Europe as well as to the Rickettsia sp.IrITA3 strain. For 15 (1.4%) of the ticks, the 17kDa, ompB, gltA and ompA genes showed the greatest similarity to Rickettsia sp. strain Davousti, Rickettsia japonica and Rickettsia heilongjiangensis, all closely phylogenetically related, the former previously found in Amblyomma tholloni ticks in Africa and previously not detected in Ixodes spp. ticks. The infestation prevalence of ticks infected with rickettsial organisms was four times higher among ground foraging birds than among other bird species, but the two groups were equally competent in transmitting Rickettsia species. The birds did not seem to serve as reservoir hosts for Rickettsia spp., but in one case it seems likely that the bird was rickettsiemic and that the ticks had acquired the bacteria from the blood of the bird. In conclusion, migratory passerine birds host epidemiologically important vector ticks and Rickettsia species and contribute to the geographic distribution of spotted fever rickettsial agents and their diseases

    Significant benefits of AIP testing and clinical screening in familial isolated and young-onset pituitary tumors

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    Context Germline mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene are responsible for a subset of familial isolated pituitary adenoma (FIPA) cases and sporadic pituitary neuroendocrine tumors (PitNETs). Objective To compare prospectively diagnosed AIP mutation-positive (AIPmut) PitNET patients with clinically presenting patients and to compare the clinical characteristics of AIPmut and AIPneg PitNET patients. Design 12-year prospective, observational study. Participants & Setting We studied probands and family members of FIPA kindreds and sporadic patients with disease onset ≀18 years or macroadenomas with onset ≀30 years (n = 1477). This was a collaborative study conducted at referral centers for pituitary diseases. Interventions & Outcome AIP testing and clinical screening for pituitary disease. Comparison of characteristics of prospectively diagnosed (n = 22) vs clinically presenting AIPmut PitNET patients (n = 145), and AIPmut (n = 167) vs AIPneg PitNET patients (n = 1310). Results Prospectively diagnosed AIPmut PitNET patients had smaller lesions with less suprasellar extension or cavernous sinus invasion and required fewer treatments with fewer operations and no radiotherapy compared with clinically presenting cases; there were fewer cases with active disease and hypopituitarism at last follow-up. When comparing AIPmut and AIPneg cases, AIPmut patients were more often males, younger, more often had GH excess, pituitary apoplexy, suprasellar extension, and more patients required multimodal therapy, including radiotherapy. AIPmut patients (n = 136) with GH excess were taller than AIPneg counterparts (n = 650). Conclusions Prospectively diagnosed AIPmut patients show better outcomes than clinically presenting cases, demonstrating the benefits of genetic and clinical screening. AIP-related pituitary disease has a wide spectrum ranging from aggressively growing lesions to stable or indolent disease course

    Epidemiological and Bacteriological Aspects of Spotted Fever Rickettsioses in Humans, Vectors and Mammals in Sweden

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    Rickettsiae are obligate intracellular gram-negative bacteria transmitted by arthropod vectors. Rickettsiae sometimes cause disease in humans, typically with high fever, headache and occasionally an eschar. In Sweden, Rickettsia helvetica, belonging to the spotted fever group, is the only tick-transmitted rickettsia found free in nature. The pathogenic roll of R. helvetica has not been fully investigated, but it has been implicated in aneruptive fever and cardiac disease. This thesis describes parts of the transmission pathways of rickettsiae in Sweden. Rickettsia infection rates in ticks collected from birds were analysed, and the birds’ role as disseminators and reservoirs was studied. We found that more than one in ten ticks was infected with rickettsia bacteria, predominantly R. helvetica, and that migrating birds contribute not only to long-distance dispersion of bacteria, but also to an inflow of novel and potentially pathogenic rickettsia species, in this case R. monacensis and R. sp. strain Davousti-like species, into Sweden. Further, wild and domestic animals were found to have seroreactivity against R. helvetica, which shows that they are exposed and susceptible to rickettsia. Their role as reservoirs has not been determined, yet they may indirectly be involved in transmission of rickettsia to humans by infected ticks feeding on them. The seroreactivity in humans was also studied. Patients investigated for suspected Borrelioses and blood donors had detectable antibodies against Rickettsia spp., with the highest prevalence detected in the suspected Borreliosis group. This shows that humans in Sweden are exposed to and develop an immune response against rickettsia. The suspicion that R. helvetica may cause severe symptoms was verified by a patient with subacute meningitis where the bacterium was shown for the first time to cause an invasive infection with CNS involvement and where the bacterium was isolated from the patient’s cerebrospinal fluid. Growth characteristics and morphology of R. helvetica were studied to better understand invasiveness and virulence. The findings indicate that the invasiveness is comparable with other rickettsia, though R. helvetica seems to have a stable but slightly slower growth.  Rickettsia helvetica is endemic in Sweden and therefore needs to be considered when investigating disease after a tick bite.Rickettsia Ă€r en liten, strikt intracellulĂ€r, gramnegativ bakterie som sprids med vektorer som fĂ€stingar, löss och loppor. Bakterien kan orsaka Rickettsios hos mĂ€nniska, en sjukdom dĂ€r de vanligaste symtomen Ă€r hög feber, huvudvĂ€rk, muskelvĂ€rk och i vissa fall ett bettmĂ€rke (eschar). I Sverige Ă€r Rickettsia helvetica, som tillhör spotted fever gruppen (SFG), den enda fĂ€stingöverförda rickettsia bakterien som hittats allmĂ€nt i naturen. Patogeniciteten för R. helvetica Ă€r ofullstĂ€ndigt utredd, men ”aneruptive fever” och hjĂ€rtmuskelinflammation har rapporterats. Avhandlingen beskriver delar av smittkedjan för SFG rickettsia i Sverige. Bakteriernas förekomst i fĂ€stingar plockade frĂ„n fĂ„glar har studerats, likasĂ„ det ekologiska tryck som flyttfĂ„glars bĂ€rarskap av infekterade fĂ€stingar bidrar med nĂ€r de korsar olika vĂ€rldsdelar. Mer Ă€n var tionde fĂ€sting var infekterad med rickettsia bakterier, i huvudsak R. helvetica. Det visade sig att flyttfĂ„glar bidrar inte bara till lĂ„ngvĂ€ga spridning av bakterier utan Ă€ven till införsel av nya potentiellt patogena rickettsiaarter, i detta fall identifierades R. monacensis och en R. sp strain Davousti liknande art. Vidare analyserades seroreaktivitet mot Rickettsia helvetica hos bĂ„de tamdjur och vilda djur, vilket visade pĂ„ antikroppsutveckling, som uttryck för smittexposition, i mer Ă€n vart femte djur. Djurens roll som reservoar för bakterien Ă€r inte klarlagd, men oavsett Ă€r djuren indirekt involverade i spridningen av bakterien till mĂ€nniska via infekterade fĂ€stingar som suger blod. Seroreaktivitet hos mĂ€nniska har ocksĂ„ studerats. Patienter, provtagna pĂ„ grund av misstanke om borreliainfektion, samt blodgivare hade detekterbara antikroppar mot Rickettsiae, med högst prevalens i gruppen med misstĂ€nkt borreliainfektion. Fynden visar att mĂ€nniskor i Sverige Ă€r exponerade för och utvecklar en immunreaktion mot rickettsia. Att R. helvetica skulle kunna ge allvarlig sjukdom verifieras av ett patientfall med subakut meningit dĂ€r bakterien för första gĂ„ngen visats ge invasiv infektion med pĂ„verkan pĂ„ nervsystemet (CNS engagemang) och dĂ€r bakterien isolerats frĂ„n patientens ryggmĂ€rgsvĂ€tska.  Morfologi och tillvĂ€xtegenskaper för R. helvetica undersöktes för att bĂ€ttre förstĂ„ bakteriens invasivitet och virulens. Fynden indikerar att invasiviteten Ă€r jĂ€mförbar med andra rickettsiaarter men R. helvetica verkar ha en stabil men nĂ„got lĂ„ngsammare tillvĂ€xt. Rickettsia helvetica Ă€r endemisk i Sverige och mĂ„ste tas i beaktande vid sjukdomsutredning efter ett fĂ€stingbett

    Epidemiological and Bacteriological Aspects of Spotted Fever Rickettsioses in Humans, Vectors and Mammals in Sweden

    No full text
    Rickettsiae are obligate intracellular gram-negative bacteria transmitted by arthropod vectors. Rickettsiae sometimes cause disease in humans, typically with high fever, headache and occasionally an eschar. In Sweden, Rickettsia helvetica, belonging to the spotted fever group, is the only tick-transmitted rickettsia found free in nature. The pathogenic roll of R. helvetica has not been fully investigated, but it has been implicated in aneruptive fever and cardiac disease. This thesis describes parts of the transmission pathways of rickettsiae in Sweden. Rickettsia infection rates in ticks collected from birds were analysed, and the birds’ role as disseminators and reservoirs was studied. We found that more than one in ten ticks was infected with rickettsia bacteria, predominantly R. helvetica, and that migrating birds contribute not only to long-distance dispersion of bacteria, but also to an inflow of novel and potentially pathogenic rickettsia species, in this case R. monacensis and R. sp. strain Davousti-like species, into Sweden. Further, wild and domestic animals were found to have seroreactivity against R. helvetica, which shows that they are exposed and susceptible to rickettsia. Their role as reservoirs has not been determined, yet they may indirectly be involved in transmission of rickettsia to humans by infected ticks feeding on them. The seroreactivity in humans was also studied. Patients investigated for suspected Borrelioses and blood donors had detectable antibodies against Rickettsia spp., with the highest prevalence detected in the suspected Borreliosis group. This shows that humans in Sweden are exposed to and develop an immune response against rickettsia. The suspicion that R. helvetica may cause severe symptoms was verified by a patient with subacute meningitis where the bacterium was shown for the first time to cause an invasive infection with CNS involvement and where the bacterium was isolated from the patient’s cerebrospinal fluid. Growth characteristics and morphology of R. helvetica were studied to better understand invasiveness and virulence. The findings indicate that the invasiveness is comparable with other rickettsia, though R. helvetica seems to have a stable but slightly slower growth.  Rickettsia helvetica is endemic in Sweden and therefore needs to be considered when investigating disease after a tick bite.Rickettsia Ă€r en liten, strikt intracellulĂ€r, gramnegativ bakterie som sprids med vektorer som fĂ€stingar, löss och loppor. Bakterien kan orsaka Rickettsios hos mĂ€nniska, en sjukdom dĂ€r de vanligaste symtomen Ă€r hög feber, huvudvĂ€rk, muskelvĂ€rk och i vissa fall ett bettmĂ€rke (eschar). I Sverige Ă€r Rickettsia helvetica, som tillhör spotted fever gruppen (SFG), den enda fĂ€stingöverförda rickettsia bakterien som hittats allmĂ€nt i naturen. Patogeniciteten för R. helvetica Ă€r ofullstĂ€ndigt utredd, men ”aneruptive fever” och hjĂ€rtmuskelinflammation har rapporterats. Avhandlingen beskriver delar av smittkedjan för SFG rickettsia i Sverige. Bakteriernas förekomst i fĂ€stingar plockade frĂ„n fĂ„glar har studerats, likasĂ„ det ekologiska tryck som flyttfĂ„glars bĂ€rarskap av infekterade fĂ€stingar bidrar med nĂ€r de korsar olika vĂ€rldsdelar. Mer Ă€n var tionde fĂ€sting var infekterad med rickettsia bakterier, i huvudsak R. helvetica. Det visade sig att flyttfĂ„glar bidrar inte bara till lĂ„ngvĂ€ga spridning av bakterier utan Ă€ven till införsel av nya potentiellt patogena rickettsiaarter, i detta fall identifierades R. monacensis och en R. sp strain Davousti liknande art. Vidare analyserades seroreaktivitet mot Rickettsia helvetica hos bĂ„de tamdjur och vilda djur, vilket visade pĂ„ antikroppsutveckling, som uttryck för smittexposition, i mer Ă€n vart femte djur. Djurens roll som reservoar för bakterien Ă€r inte klarlagd, men oavsett Ă€r djuren indirekt involverade i spridningen av bakterien till mĂ€nniska via infekterade fĂ€stingar som suger blod. Seroreaktivitet hos mĂ€nniska har ocksĂ„ studerats. Patienter, provtagna pĂ„ grund av misstanke om borreliainfektion, samt blodgivare hade detekterbara antikroppar mot Rickettsiae, med högst prevalens i gruppen med misstĂ€nkt borreliainfektion. Fynden visar att mĂ€nniskor i Sverige Ă€r exponerade för och utvecklar en immunreaktion mot rickettsia. Att R. helvetica skulle kunna ge allvarlig sjukdom verifieras av ett patientfall med subakut meningit dĂ€r bakterien för första gĂ„ngen visats ge invasiv infektion med pĂ„verkan pĂ„ nervsystemet (CNS engagemang) och dĂ€r bakterien isolerats frĂ„n patientens ryggmĂ€rgsvĂ€tska.  Morfologi och tillvĂ€xtegenskaper för R. helvetica undersöktes för att bĂ€ttre förstĂ„ bakteriens invasivitet och virulens. Fynden indikerar att invasiviteten Ă€r jĂ€mförbar med andra rickettsiaarter men R. helvetica verkar ha en stabil men nĂ„got lĂ„ngsammare tillvĂ€xt. Rickettsia helvetica Ă€r endemisk i Sverige och mĂ„ste tas i beaktande vid sjukdomsutredning efter ett fĂ€stingbett

    Epidemiological and Bacteriological Aspects of Spotted Fever Rickettsioses in Humans, Vectors and Mammals in Sweden

    No full text
    Rickettsiae are obligate intracellular gram-negative bacteria transmitted by arthropod vectors. Rickettsiae sometimes cause disease in humans, typically with high fever, headache and occasionally an eschar. In Sweden, Rickettsia helvetica, belonging to the spotted fever group, is the only tick-transmitted rickettsia found free in nature. The pathogenic roll of R. helvetica has not been fully investigated, but it has been implicated in aneruptive fever and cardiac disease. This thesis describes parts of the transmission pathways of rickettsiae in Sweden. Rickettsia infection rates in ticks collected from birds were analysed, and the birds’ role as disseminators and reservoirs was studied. We found that more than one in ten ticks was infected with rickettsia bacteria, predominantly R. helvetica, and that migrating birds contribute not only to long-distance dispersion of bacteria, but also to an inflow of novel and potentially pathogenic rickettsia species, in this case R. monacensis and R. sp. strain Davousti-like species, into Sweden. Further, wild and domestic animals were found to have seroreactivity against R. helvetica, which shows that they are exposed and susceptible to rickettsia. Their role as reservoirs has not been determined, yet they may indirectly be involved in transmission of rickettsia to humans by infected ticks feeding on them. The seroreactivity in humans was also studied. Patients investigated for suspected Borrelioses and blood donors had detectable antibodies against Rickettsia spp., with the highest prevalence detected in the suspected Borreliosis group. This shows that humans in Sweden are exposed to and develop an immune response against rickettsia. The suspicion that R. helvetica may cause severe symptoms was verified by a patient with subacute meningitis where the bacterium was shown for the first time to cause an invasive infection with CNS involvement and where the bacterium was isolated from the patient’s cerebrospinal fluid. Growth characteristics and morphology of R. helvetica were studied to better understand invasiveness and virulence. The findings indicate that the invasiveness is comparable with other rickettsia, though R. helvetica seems to have a stable but slightly slower growth.  Rickettsia helvetica is endemic in Sweden and therefore needs to be considered when investigating disease after a tick bite.Rickettsia Ă€r en liten, strikt intracellulĂ€r, gramnegativ bakterie som sprids med vektorer som fĂ€stingar, löss och loppor. Bakterien kan orsaka Rickettsios hos mĂ€nniska, en sjukdom dĂ€r de vanligaste symtomen Ă€r hög feber, huvudvĂ€rk, muskelvĂ€rk och i vissa fall ett bettmĂ€rke (eschar). I Sverige Ă€r Rickettsia helvetica, som tillhör spotted fever gruppen (SFG), den enda fĂ€stingöverförda rickettsia bakterien som hittats allmĂ€nt i naturen. Patogeniciteten för R. helvetica Ă€r ofullstĂ€ndigt utredd, men ”aneruptive fever” och hjĂ€rtmuskelinflammation har rapporterats. Avhandlingen beskriver delar av smittkedjan för SFG rickettsia i Sverige. Bakteriernas förekomst i fĂ€stingar plockade frĂ„n fĂ„glar har studerats, likasĂ„ det ekologiska tryck som flyttfĂ„glars bĂ€rarskap av infekterade fĂ€stingar bidrar med nĂ€r de korsar olika vĂ€rldsdelar. Mer Ă€n var tionde fĂ€sting var infekterad med rickettsia bakterier, i huvudsak R. helvetica. Det visade sig att flyttfĂ„glar bidrar inte bara till lĂ„ngvĂ€ga spridning av bakterier utan Ă€ven till införsel av nya potentiellt patogena rickettsiaarter, i detta fall identifierades R. monacensis och en R. sp strain Davousti liknande art. Vidare analyserades seroreaktivitet mot Rickettsia helvetica hos bĂ„de tamdjur och vilda djur, vilket visade pĂ„ antikroppsutveckling, som uttryck för smittexposition, i mer Ă€n vart femte djur. Djurens roll som reservoar för bakterien Ă€r inte klarlagd, men oavsett Ă€r djuren indirekt involverade i spridningen av bakterien till mĂ€nniska via infekterade fĂ€stingar som suger blod. Seroreaktivitet hos mĂ€nniska har ocksĂ„ studerats. Patienter, provtagna pĂ„ grund av misstanke om borreliainfektion, samt blodgivare hade detekterbara antikroppar mot Rickettsiae, med högst prevalens i gruppen med misstĂ€nkt borreliainfektion. Fynden visar att mĂ€nniskor i Sverige Ă€r exponerade för och utvecklar en immunreaktion mot rickettsia. Att R. helvetica skulle kunna ge allvarlig sjukdom verifieras av ett patientfall med subakut meningit dĂ€r bakterien för första gĂ„ngen visats ge invasiv infektion med pĂ„verkan pĂ„ nervsystemet (CNS engagemang) och dĂ€r bakterien isolerats frĂ„n patientens ryggmĂ€rgsvĂ€tska.  Morfologi och tillvĂ€xtegenskaper för R. helvetica undersöktes för att bĂ€ttre förstĂ„ bakteriens invasivitet och virulens. Fynden indikerar att invasiviteten Ă€r jĂ€mförbar med andra rickettsiaarter men R. helvetica verkar ha en stabil men nĂ„got lĂ„ngsammare tillvĂ€xt. Rickettsia helvetica Ă€r endemisk i Sverige och mĂ„ste tas i beaktande vid sjukdomsutredning efter ett fĂ€stingbett

    The Heureka forestry decision support system : an overview

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    Mathematical programming and computers have been used for several decades to solve complex and long term forest management planning problems. The ever increasing demand on the forest ecosystem to produce wood and other goods and services poses a corresponding demand on a forest decision support system. As a response to meet new requirements the development of the Heureka system was initiated at SLU in 2002 and a first version of the system was released in 2009. Based on a common kernel, a number or applications of the system for different problem areas and users have been developed. The three main applications are made up by an interactive stand simulator, a tool for long term forest level planning containing an optimization module, and a simulator for regional analyses. The system contains models for growth projections, simulation of treatments, estimation of recreation values and carbon sequestration, and habitat suitability. It is also possible to make projections under different climate scenarios. In addition the system includes a number of supporting applications for importing data from different sources, for field inventory, and for comparing and ranking alternative management plans
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