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Rationale & Objective: Approximately 11% of people with kidney failure worldwide are treated with peritoneal dialysis (PD). This study examined PD use and practice patterns across the globe. Study Design: A cross-sectional survey. Setting & Participants: Stakeholders including clinicians, policy makers, and patient representatives in 182 countries convened by the International Society of Nephrology between July and September 2018. Outcome(s): PD use, availability, accessibility, affordability, delivery, and reporting of quality outcome measures. Analytical Approach: Descriptive statistics. Result(s): Responses were received from 88% (n = 160) of countries and there were 313 participants (257 nephrologists [82%], 22 non-nephrologist physicians [7%], 6 other health professionals [2%], 17 administrators/policy makers/civil servants [5%], and 11 others [4%]). 85% (n = 156) of countries responded to questions about PD. Median PD use was 38.1 per million population. PD was not available in 30 of the 156 (19%) countries responding to PD-related questions, particularly in countries in Africa (20/41) and low-income countries (15/22). In 69% of countries, PD was the initial dialysis modality for <=10% of patients with newly diagnosed kidney failure. Patients receiving PD were expected to pay 1% to 25% of treatment costs, and higher (>75%) copayments (out-of-pocket expenses incurred by patients) were more common in South Asia and low-income countries. Average exchange volumes were adequate (defined as 3-4 exchanges per day or the equivalent for automated PD) in 72% of countries. PD quality outcome monitoring and reporting were variable. Most countries did not measure patient-reported PD outcomes. Limitation(s): Low responses from policy makers; limited ability to provide more in-depth explanations underpinning outcomes from each country due to lack of granular data; lack of objective data. Conclusion(s): Large inter- and intraregional disparities exist in PD availability, acce

Rationale & Objective: Hemodialysis (HD) is the most common form of kidney replacement therapy. This study aimed to examine the use, availability, accessibility, affordability, and quality of HD care worldwide. Study Design: A cross-sectional survey. Setting & Participants: Stakeholders (clinicians, policy makers, and consumer representatives) in 182 countries were convened by the International Society of Nephrology from July to September 2018. Outcome(s): Use, availability, accessibility, affordability, and quality of HD care. Analytical Approach: Descriptive statistics. Result(s): Overall, representatives from 160 (88%) countries participated. Median country-specific use of maintenance HD was 298.4 (IQR, 80.5-599.4) per million population (pmp). Global median HD use among incident patients with kidney failure was 98.0 (IQR, 81.5-140.8) pmp and median number of HD centers was 4.5 (IQR, 1.2-9.9) pmp. Adequate HD services (3-4 hours 3 times weekly) were generally available in 27% of low-income countries. Home HD was generally available in 36% of high-income countries. 32% of countries performed monitoring of patient-reported outcomes; 61%, monitoring of small-solute clearance; 60%, monitoring of bone mineral markers; 51%, monitoring of technique survival; and 60%, monitoring of patient survival. At initiation of maintenance dialysis, only 5% of countries used an arteriovenous access in almost all patients. Vascular access education was suboptimal, funding for vascular access procedures was not uniform, and copayments were greater in countries with lower levels of income. Patients in 23% of the low-income countries had to pay >75% of HD costs compared with patients in only 4% of high-income countries. Limitation(s): A cross-sectional survey with possibility of response bias, social desirability bias, and limited data collection preventing in-depth analysis. Conclusion(s): In summary, findings reveal substantial variations in global HD use, availability, accessibility

Diseases of the glomerular basement membrane (GBM), such as Goodpasture's disease (GP) and Alport syndrome (AS), are a major cause of chronic kidney failure and an unmet medical need. Collagen IValpha345 is an important architectural element of the GBM that was discovered in previous research on GP and AS. How this collagen enables GBM to function as a permselective filter and how structural defects cause renal failure remain an enigma. We found a distinctive genetic variant of collagen IValpha345 in both a familial GP case and four AS kindreds that provided insights into these mechanisms. The variant is an 8-residue appendage at the C-terminus of the alpha3 subunit of the alpha345 hexamer. A knock-in mouse harboring the variant displayed GBM abnormalities and proteinuria. This pathology phenocopied AS, which pinpointed the alpha345 hexamer as a focal point in GBM function and dysfunction. Crystallography and assembly studies revealed underlying hexamer mechanisms, as described in Boudko et al. and Pedchenko et al. Bioactive sites on the hexamer surface were identified where pathogenic pathways of GP and AS converge and, potentially, that of diabetic nephropathy (DN). We conclude that the hexamer functions include signaling and organizing macromolecular complexes, which enable GBM assembly and function. Therapeutic modulation or replacement of alpha345 hexamer could therefore be a potential treatment for GBM diseases, and this knock-in mouse model is suitable for developing gene therapies.Copyright © 2021 THE AUTHORS. Published by Elsevier Inc on behalf of American Society for Biochemistry and Molecular Biology. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

BACKGROUND: Health information systems (HIS) are fundamental tools for the surveillance of health services, estimation of disease burden and prioritization of health resources. Several gaps in the availability of HIS for kidney disease were highlighted by the first iteration of the Global Kidney Health Atlas. METHOD(S): As part of its second iteration, the International Society of Nephrology conducted a cross-sectional global survey between July and October 2018 to explore the coverage and scope of HIS for kidney disease, with a focus on kidney replacement therapy (KRT). RESULT(S): Out of a total of 182 invited countries, 154 countries responded to questions on HIS (85% response rate). KRT registries were available in almost all high-income countries, but few low-income countries, while registries for non-dialysis chronic kidney disease (CKD) or acute kidney injury (AKI) were rare. Registries in high-income countries tended to be national, in contrast to registries in low-income countries, which often operated at local or regional levels. Although cause of end-stage kidney disease, modality of KRT and source of kidney transplant donors were frequently reported, few countries collected data on patient-reported outcome measures and only half of low-income countries recorded process-based measures. Almost no countries had programs to detect AKI and practices to identify CKD-targeted individuals with diabetes, hypertension and cardiovascular disease, rather than members of high-risk ethnic groups. CONCLUSION(S): These findings confirm significant heterogeneity in the global availability of HIS for kidney disease and highlight important gaps in their coverage and scope, especially in low-income countries and across the domains of AKI, non-dialysis CKD, patient-reported outcomes, process-based measures and quality indicators for KRT service delivery.Copyright © The Author(s) 2020. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

Diseases of the glomerular basement membrane (GBM), such as Goodpasture's disease (GP) and Alport syndrome (AS), are a major cause of chronic kidney failure and an unmet medical need. Collagen IValpha345 is an important architectural element of the GBM that was discovered in previous research on GP and AS. How this collagen enables GBM to function as a permselective filter and how structural defects cause renal failure remain an enigma. We found a distinctive genetic variant of collagen IValpha345 in both a familial GP case and four AS kindreds that provided insights into these mechanisms. The variant is an 8-residue appendage at the C-terminus of the alpha3 subunit of the alpha345 hexamer. A knock-in mouse harboring the variant displayed GBM abnormalities and proteinuria. This pathology phenocopied AS, which pinpointed the alpha345 hexamer as a focal point in GBM function and dysfunction. Crystallography and assembly studies revealed underlying hexamer mechanisms, as described in Companion Papers II and III. Bioactive sites on the hexamer surface were identified where pathogenic pathways of GP and AS converge, and, potentially, that of diabetic nephropathy (DN). We conclude that the hexamer functions include signaling and organizing macromolecular complexes, which enable GBM assembly and function. Therapeutic modulation or replacement of alpha345 hexamer could therefore be a potential treatment for GBM diseases, and this knock-in mouse model is suitable for developing gene therapies.Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.

Rationale & Objective: Approximately 11% of people with kidney failure worldwide are treated with peritoneal dialysis (PD). This study examined PD use and practice patterns across the globe. Study Design: A cross-sectional survey. Setting & Participants: Stakeholders including clinicians, policy makers, and patient representatives in 182 countries convened by the International Society of Nephrology between July and September 2018. Outcome(s): PD use, availability, accessibility, affordability, delivery, and reporting of quality outcome measures. Analytical Approach: Descriptive statistics. Result(s): Responses were received from 88% (n = 160) of countries and there were 313 participants (257 nephrologists [82%], 22 non-nephrologist physicians [7%], 6 other health professionals [2%], 17 administrators/policy makers/civil servants [5%], and 11 others [4%]). 85% (n = 156) of countries responded to questions about PD. Median PD use was 38.1 per million population. PD was not available in 30 of the 156 (19%) countries responding to PD-related questions, particularly in countries in Africa (20/41) and low-income countries (15/22). In 69% of countries, PD was the initial dialysis modality for <=10% of patients with newly diagnosed kidney failure. Patients receiving PD were expected to pay 1% to 25% of treatment costs, and higher (>75%) copayments (out-of-pocket expenses incurred by patients) were more common in South Asia and low-income countries. Average exchange volumes were adequate (defined as 3-4 exchanges per day or the equivalent for automated PD) in 72% of countries. PD quality outcome monitoring and reporting were variable. Most countries did not measure patient-reported PD outcomes. Limitation(s): Low responses from policy makers; limited ability to provide more in-depth explanations underpinning outcomes from each country due to lack of granular data; lack of objective data. Conclusion(s): Large inter- and intraregional disparities exist in PD availability, acce

Rationale & Objective: Hemodialysis (HD) is the most common form of kidney replacement therapy. This study aimed to examine the use, availability, accessibility, affordability, and quality of HD care worldwide. Study Design: A cross-sectional survey. Setting & Participants: Stakeholders (clinicians, policy makers, and consumer representatives) in 182 countries were convened by the International Society of Nephrology from July to September 2018. Outcome(s): Use, availability, accessibility, affordability, and quality of HD care. Analytical Approach: Descriptive statistics. Result(s): Overall, representatives from 160 (88%) countries participated. Median country-specific use of maintenance HD was 298.4 (IQR, 80.5-599.4) per million population (pmp). Global median HD use among incident patients with kidney failure was 98.0 (IQR, 81.5-140.8) pmp and median number of HD centers was 4.5 (IQR, 1.2-9.9) pmp. Adequate HD services (3-4 hours 3 times weekly) were generally available in 27% of low-income countries. Home HD was generally available in 36% of high-income countries. 32% of countries performed monitoring of patient-reported outcomes; 61%, monitoring of small-solute clearance; 60%, monitoring of bone mineral markers; 51%, monitoring of technique survival; and 60%, monitoring of patient survival. At initiation of maintenance dialysis, only 5% of countries used an arteriovenous access in almost all patients. Vascular access education was suboptimal, funding for vascular access procedures was not uniform, and copayments were greater in countries with lower levels of income. Patients in 23% of the low-income countries had to pay >75% of HD costs compared with patients in only 4% of high-income countries. Limitation(s): A cross-sectional survey with possibility of response bias, social desirability bias, and limited data collection preventing in-depth analysis. Conclusion(s): In summary, findings reveal substantial variations in global HD use, availability, accessibility

BACKGROUND: Health information systems (HIS) are fundamental tools for the surveillance of health services, estimation of disease burden and prioritization of health resources. Several gaps in the availability of HIS for kidney disease were highlighted by the first iteration of the Global Kidney Health Atlas. METHOD(S): As part of its second iteration, the International Society of Nephrology conducted a cross-sectional global survey between July and October 2018 to explore the coverage and scope of HIS for kidney disease, with a focus on kidney replacement therapy (KRT). RESULT(S): Out of a total of 182 invited countries, 154 countries responded to questions on HIS (85% response rate). KRT registries were available in almost all high-income countries, but few low-income countries, while registries for non-dialysis chronic kidney disease (CKD) or acute kidney injury (AKI) were rare. Registries in high-income countries tended to be national, in contrast to registries in low-income countries, which often operated at local or regional levels. Although cause of end-stage kidney disease, modality of KRT and source of kidney transplant donors were frequently reported, few countries collected data on patient-reported outcome measures and only half of low-income countries recorded process-based measures. Almost no countries had programs to detect AKI and practices to identify CKD-targeted individuals with diabetes, hypertension and cardiovascular disease, rather than members of high-risk ethnic groups. CONCLUSION(S): These findings confirm significant heterogeneity in the global availability of HIS for kidney disease and highlight important gaps in their coverage and scope, especially in low-income countries and across the domains of AKI, non-dialysis CKD, patient-reported outcomes, process-based measures and quality indicators for KRT service delivery.Copyright © The Author(s) 2020. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

Diseases of the glomerular basement membrane (GBM), such as Goodpasture's disease (GP) and Alport syndrome (AS), are a major cause of chronic kidney failure and an unmet medical need. Collagen IValpha345 is an important architectural element of the GBM that was discovered in previous research on GP and AS. How this collagen enables GBM to function as a permselective filter and how structural defects cause renal failure remain an enigma. We found a distinctive genetic variant of collagen IValpha345 in both a familial GP case and four AS kindreds that provided insights into these mechanisms. The variant is an 8-residue appendage at the C-terminus of the alpha3 subunit of the alpha345 hexamer. A knock-in mouse harboring the variant displayed GBM abnormalities and proteinuria. This pathology phenocopied AS, which pinpointed the alpha345 hexamer as a focal point in GBM function and dysfunction. Crystallography and assembly studies revealed underlying hexamer mechanisms, as described in Companion Papers II and III. Bioactive sites on the hexamer surface were identified where pathogenic pathways of GP and AS converge, and, potentially, that of diabetic nephropathy (DN). We conclude that the hexamer functions include signaling and organizing macromolecular complexes, which enable GBM assembly and function. Therapeutic modulation or replacement of alpha345 hexamer could therefore be a potential treatment for GBM diseases, and this knock-in mouse model is suitable for developing gene therapies.Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.

Background: Antiglomerular basement membrane (anti-GBM) disease is associated with HLA-DRB1*1501 (the major predisposing genetic factor in the disease), with alpha3127-148 as a nephritogenic T and B cell epitope. Although the cause of disease remains unclear, the association of infections with anti-GBM disease hasbeenlong suspected. Method(s): To investigate whether microbesmight activate autoreactive T and B lymphocytes via molecular mimicry in anti-GBM disease, we used bioinformatic tools, including BLAST, SYFPEITHI, and ABCpred, for peptide searching and epitope prediction. We used sera from patients with anti-GBM disease to assess peptides recognized by antibodies, and immunized WKY rats and a humanized mouse model (HLA-DR15 transgenic mice) with each of the peptide candidates to assess pathogenicity. Result(s): Onthe basis of the criticalmotif, the bioinformatic approach identified 36 microbial peptides thatmimic human alpha3127-148. Circulating antibodies in sera from patients with anti-GBM recognized nine of them. One peptide, B7, derived from Actinomyces species, induced proteinuria, linear IgG deposition on the GBM, and crescent formation when injected into WKY rats. The antibodies to B7 also targeted human and rat alpha3127-148. B7 induced T cell activation from human alpha3127-148-immunized rats. T cell responses to B7 were detected in rats immunized by Actinomyces lysate proteins or recombinant proteins. We confirmed B7's pathogenicity in HLADR15 transgenic mice that developed kidney injury similar to that observed in a3135-145-immunized mice. Conclusion(s): Sera from patients with anti-GBM disease recognizedmicrobial peptides identified through a bioinformatic approach, and a peptide fromActinomycesinduced experimental anti-GBMGNbyTandBcell crossreactivity. These studies demonstrate that anti-GBM disease may be initiated by immunization with a microbial peptide.Copyright © 2020 by the American Society of Nephrology.

Background: Antiglomerular basement membrane (anti-GBM) disease is associated with HLA-DRB1*1501 (the major predisposing genetic factor in the disease), with alpha3127-148 as a nephritogenic T and B cell epitope. Although the cause of disease remains unclear, the association of infections with anti-GBM disease hasbeenlong suspected. Method(s): To investigate whether microbesmight activate autoreactive T and B lymphocytes via molecular mimicry in anti-GBM disease, we used bioinformatic tools, including BLAST, SYFPEITHI, and ABCpred, for peptide searching and epitope prediction. We used sera from patients with anti-GBM disease to assess peptides recognized by antibodies, and immunized WKY rats and a humanized mouse model (HLA-DR15 transgenic mice) with each of the peptide candidates to assess pathogenicity. Result(s): Onthe basis of the criticalmotif, the bioinformatic approach identified 36 microbial peptides thatmimic human alpha3127-148. Circulating antibodies in sera from patients with anti-GBM recognized nine of them. One peptide, B7, derived from Actinomyces species, induced proteinuria, linear IgG deposition on the GBM, and crescent formation when injected into WKY rats. The antibodies to B7 also targeted human and rat alpha3127-148. B7 induced T cell activation from human alpha3127-148-immunized rats. T cell responses to B7 were detected in rats immunized by Actinomyces lysate proteins or recombinant proteins. We confirmed B7's pathogenicity in HLADR15 transgenic mice that developed kidney injury similar to that observed in a3135-145-immunized mice. Conclusion(s): Sera from patients with anti-GBM disease recognizedmicrobial peptides identified through a bioinformatic approach, and a peptide fromActinomycesinduced experimental anti-GBMGNbyTandBcell crossreactivity. These studies demonstrate that anti-GBM disease may be initiated by immunization with a microbial peptide.Copyright © 2020 by the American Society of Nephrology.

Objective To determine the global capacity (availability, accessibility, quality, and affordability) to deliver kidney replacement therapy (dialysis and transplantation) and conservative kidney management. Design International cross sectional survey. Setting International Society of Nephrology (ISN) survey of 182 countries from July to September 2018. Participants Key stakeholders identified by ISN's national and regional leaders. Main outcome measures Markers of national capacity to deliver core components of kidney replacement therapy and conservative kidney management. Results Responses were received from 160 (87.9%) of 182 countries, comprising 97.8% (7338.5 million of 7501.3 million) of the world's population. A wide variation was found in capacity and structures for kidney replacement therapy and conservative kidney management-namely, funding mechanisms, health workforce, service delivery, and available technologies. Information on the prevalence of treated end stage kidney disease was available in 91 (42%) of 218 countries worldwide. Estimates varied more than 800-fold from 4 to 3392 per million population. Rwanda was the only low income country to report data on the prevalence of treated disease; 5 (<10%) of 53 African countries reported these data. Of 159 countries, 102 (64%) provided public funding for kidney replacement therapy. Sixty eight (43%) of 159 countries charged no fees at the point of care delivery and 34 (21%) made some charge. Haemodialysis was reported as available in 156 (100%) of 156 countries, peritoneal dialysis in 119 (76%) of 156 countries, and kidney transplantation in 114 (74%) of 155 countries. Dialysis and kidney transplantation were available to more than 50% of patients in only 108 (70%) and 45 (29%) of 154 countries that offered these services, respectively. Conservative kidney management was available in 124 (81%) of 154 countries. Worldwide, the median number of nephrologists was 9.96 per million population, which varied with i

Objective To determine the global capacity (availability, accessibility, quality, and affordability) to deliver kidney replacement therapy (dialysis and transplantation) and conservative kidney management. Design International cross sectional survey. Setting International Society of Nephrology (ISN) survey of 182 countries from July to September 2018. Participants Key stakeholders identified by ISN's national and regional leaders. Main outcome measures Markers of national capacity to deliver core components of kidney replacement therapy and conservative kidney management. Results Responses were received from 160 (87.9%) of 182 countries, comprising 97.8% (7338.5 million of 7501.3 million) of the world's population. A wide variation was found in capacity and structures for kidney replacement therapy and conservative kidney management-namely, funding mechanisms, health workforce, service delivery, and available technologies. Information on the prevalence of treated end stage kidney disease was available in 91 (42%) of 218 countries worldwide. Estimates varied more than 800-fold from 4 to 3392 per million population. Rwanda was the only low income country to report data on the prevalence of treated disease; 5 (<10%) of 53 African countries reported these data. Of 159 countries, 102 (64%) provided public funding for kidney replacement therapy. Sixty eight (43%) of 159 countries charged no fees at the point of care delivery and 34 (21%) made some charge. Haemodialysis was reported as available in 156 (100%) of 156 countries, peritoneal dialysis in 119 (76%) of 156 countries, and kidney transplantation in 114 (74%) of 155 countries. Dialysis and kidney transplantation were available to more than 50% of patients in only 108 (70%) and 45 (29%) of 154 countries that offered these services, respectively. Conservative kidney management was available in 124 (81%) of 154 countries. Worldwide, the median number of nephrologists was 9.96 per million population, which varied with i

Reliable governance and health financing are critical to the abilities of health systems in different countries to sustainably meet the health needs of their peoples, including those with kidney disease. A comprehensive understanding of existing systems and infrastructure is therefore necessary to globally identify gaps in kidney care and prioritize areas for improvement. This multinational, cross-sectional survey, conducted by the ISN as part of the Global Kidney Health Atlas, examined the oversight, financing, and perceived quality of infrastructure for kidney care across the world. Overall, 125 countries, comprising 93% of the world's population, responded to the entire survey, with 122 countries responding to questions pertaining to this domain. National oversight of kidney care was most common in high-income countries while individual hospital oversight was most common in low-income countries. Parts of Africa and the Middle East appeared to have no organized oversight system. The proportion of countries in which health care system coverage for people with kidney disease was publicly funded and free varied for AKI (56%), nondialysis chronic kidney disease (40%), dialysis (63%), and kidney transplantation (57%), but was much less common in lower income countries, particularly Africa and Southeast Asia, which relied more heavily on private funding with out-of-pocket expenses for patients. Early detection and management of kidney disease were least likely to be covered by funding models. The perceived quality of health infrastructure supporting AKI and chronic kidney disease care was rated poor to extremely poor in none of the high-income countries but was rated poor to extremely poor in over 40% of low-income countries, particularly Africa. This study demonstrated significant gaps in oversight, funding, and infrastructure supporting health services caring for patients with kidney disease, especially in low- and middle-income countries.Copyright © 2017 Internationa

Access to essential medications and health products is critical to effective management of kidney disease. Using data from the ISN Global Kidney Health Atlas multinational cross-sectional survey, global access of patients with kidney disease to essential medications and health products was examined. Overall, 125 countries participated, with 118 countries, composing 91.5% of the world's population, providing data on this domain. Most countries were unable to access eGFR and albuminuria in their primary care settings. Only one-third of low-income countries (LICs) were able to measure serum creatinine and none were able to access eGFR or quantify proteinuria. The ability to monitor diabetes mellitus through serum glucose and glycated hemoglobin measurements was suboptimal. Pathology services were rarely available in tertiary care in LICs (12%) and lower middle-income countries (45%). While acute and chronic hemodialysis services were available in almost all countries, acute and chronic peritoneal dialysis services were rarely available in LICs (18% and 29%, respectively). Kidney transplantation was available in 79% of countries overall and in 12% of LICs. While over one-half of all countries publicly funded RRT and kidney medications with or without copayment, this was less common in LICs and lower middle-income countries. In conclusion, this study demonstrated significant gaps in services for kidney care and funding that were most apparent in LICs and lower middle-income countries.Copyright © 2017

Reliable governance and health financing are critical to the abilities of health systems in different countries to sustainably meet the health needs of their peoples, including those with kidney disease. A comprehensive understanding of existing systems and infrastructure is therefore necessary to globally identify gaps in kidney care and prioritize areas for improvement. This multinational, cross-sectional survey, conducted by the ISN as part of the Global Kidney Health Atlas, examined the oversight, financing, and perceived quality of infrastructure for kidney care across the world. Overall, 125 countries, comprising 93% of the world's population, responded to the entire survey, with 122 countries responding to questions pertaining to this domain. National oversight of kidney care was most common in high-income countries while individual hospital oversight was most common in low-income countries. Parts of Africa and the Middle East appeared to have no organized oversight system. The proportion of countries in which health care system coverage for people with kidney disease was publicly funded and free varied for AKI (56%), nondialysis chronic kidney disease (40%), dialysis (63%), and kidney transplantation (57%), but was much less common in lower income countries, particularly Africa and Southeast Asia, which relied more heavily on private funding with out-of-pocket expenses for patients. Early detection and management of kidney disease were least likely to be covered by funding models. The perceived quality of health infrastructure supporting AKI and chronic kidney disease care was rated poor to extremely poor in none of the high-income countries but was rated poor to extremely poor in over 40% of low-income countries, particularly Africa. This study demonstrated significant gaps in oversight, funding, and infrastructure supporting health services caring for patients with kidney disease, especially in low- and middle-income countries.Copyright © 2017 Internationa

The Swift Gamma-ray Burst (GRB) observatory responds to GRB triggers with optical observations in ~ 100 s, but cannot respond faster than ~ 60 s. While some ground-based telescopes respond quickly, the number of sub-60 s detections remains small. In mid- to late-2013, the Ultra-Fast Flash Observatory-Pathfinder is to be launched on the Lomonosov spacecraft to investigate early optical GRB emission. This pathfinder mission is necessarily limited in sensitivity and event rate; here we discuss a next generation rapid-response space observatory. We list science topics motivating our instruments, those that require rapid optical-IR GRB response, including: A survey of GRB rise shapes/times, measurements of optical bulk Lorentz factors, investigation of magnetic dominated (vs. non-magnetic) jet models, internal vs. external shock origin of prompt optical emission, the use of GRBs for cosmology, and dust evaporation in the GRB environment. We also address the impacts of the characteristics of GRB observing on our instrument and observatory design. We describe our instrument designs and choices for a next generation observatory as a second instrument on a low-earth orbit spacecraft, with a 120 kg instrument mass budget. Restricted to relatively modest mass and power, we find that a coded mask X-ray camera with 1024 cm2 of detector area could rapidly locate about 64 GRB triggers/year. Responding to the locations from the X-ray camera, a 30 cm aperture telescope with a beam-steering system for rapid (~ 1 s) response and a near-IR camera should detect ~ 29 GRB, given Swift GRB properties. Am additional optical camera would give a broadband optical-IR slope, allowing dynamic measurement of dust extinction at the source, for the first time., Comment: 12 pages, 11 figures, submitted to SPIE 2012 Amsterdam conference proceedings

The Swift Gamma-ray Burst (GRB) observatory responds to GRB triggers with optical observations in ~ 100 s, but cannot respond faster than ~ 60 s. While some ground-based telescopes respond quickly, the number of sub-60 s detections remains small. In mid- to late-2013, the Ultra-Fast Flash Observatory-Pathfinder is to be launched on the Lomonosov spacecraft to investigate early optical GRB emission. This pathfinder mission is necessarily limited in sensitivity and event rate; here we discuss a next generation rapid-response space observatory. We list science topics motivating our instruments, those that require rapid optical-IR GRB response, including: A survey of GRB rise shapes/times, measurements of optical bulk Lorentz factors, investigation of magnetic dominated (vs. non-magnetic) jet models, internal vs. external shock origin of prompt optical emission, the use of GRBs for cosmology, and dust evaporation in the GRB environment. We also address the impacts of the characteristics of GRB observing on our instrument and observatory design. We describe our instrument designs and choices for a next generation observatory as a second instrument on a low-earth orbit spacecraft, with a 120 kg instrument mass budget. Restricted to relatively modest mass and power, we find that a coded mask X-ray camera with 1024 cm2 of detector area could rapidly locate about 64 GRB triggers/year. Responding to the locations from the X-ray camera, a 30 cm aperture telescope with a beam-steering system for rapid (~ 1 s) response and a near-IR camera should detect ~ 29 GRB, given Swift GRB properties. Am additional optical camera would give a broadband optical-IR slope, allowing dynamic measurement of dust extinction at the source, for the first time., Comment: 12 pages, 11 figures, submitted to SPIE 2012 Amsterdam conference proceedings

The Ultra-Fast Flash Observatory-Pathfinder (UFFO-P) is to be launched onboard Lomonosov spacecraft in November 2011. It is to measure early UV/Optical photons from Gamma Ray Bursts (GRBs). Slewing Mirror Telescope (SMT) is one of two instruments designed for detection of UV/Optical images of the GRBs. SMT is a Ritchey-Chr\'etien telescope of 100 mm in diameter with a motorized slewing mirror at the entrance providing 17\times17 arcmin2 in Field of View (FOV) and 4 arcsec in pixel resolution. Its sky coverage can be further expanded up to 35 degrees in FOV by tilting a motorized slewing mirror. All mirrors were fabricated to about RMS 0.02 waves in wave front error (WFE) and 84.7% (in average reflectivity) over 200nm~650nm range. SMT was aligned to RMS 0.05 waves in WFE (test wavelength 632.8nm). From the static gravity test result, SMT optics system is expected to survive during launch. The technical details of SMT assembly and laboratory performance test results are reported., Comment: 4 pages, 6 figures, proceeding paper for the 32nd International Conference on Cosmic Rays (ICRC), Beijing, August 11-18, 2011

Hundreds of gamma-ray burst (GRB) optical light curves have been measured since the discovery of optical afterglows. However, even after nearly 7 years of operation of the Swift Observatory, only a handful of measurements have been made soon (within a minute) after the gamma ray signal. This lack of early observations fails to address burst physics at short time scales associated with prompt emissions and progenitors. Because of this lack of sub-minute data, the characteristics of the rise phase of optical light curve of short-hard type GRB and rapid-rising GRB, which may account for ~30% of all GRB, remain practically unknown. We have developed methods for reaching sub-minute and sub-second timescales in a small spacecraft observatory. Rather than slewing the entire spacecraft to aim the optical instrument at the GRB position, we use rapidly moving mirror to redirect our optical beam. As a first step, we employ motorized slewing mirror telescope (SMT), which can point to the event within 1s, in the UFFO Pathfinder GRB Telescope onboard the Lomonosov satellite to be launched in Nov. 2011. UFFO's sub-minute measurements of the optical emission of dozens of GRB each year will result in a more rigorous test of current internal shock models, probe the extremes of bulk Lorentz factors, provide the first early and detailed measurements of fast-rise GRB optical light curves, and help verify the prospect of GRB as a new standard candle. We will describe the science and the mission of the current UFFO Pathfinder project, and our plan of a full-scale UFFO-100 as the next step., Comment: 4 pages, 5 figures, to appear in the 32nd International Conference on Cosmic Rays (ICRC), Beijing, August 11-18, 2011

The Ultra-Fast Flash Observatory (UFFO) Pathfinder is a payload on the Russian Lomonosov satellite, scheduled to be launched in November 2011. The Observatory is designed to detect early UV/Optical photons from Gamma-Ray Bursts (GRBs). There are two telescopes and one main data acquisition system: the UFFO Burst Alert & Trigger Telescope (UBAT), the Slewing Mirror Telescope (SMT), and the UFFO Data Acquisition (UDAQ) system. The UDAQ controls and manages the operation and communication of each telescope, and is also in charge of the interface with the satellite. It will write the data taken by each telescope to the NOR flash memory and sends them to the satellite via the Bus-Interface system (BI). It also receives data from the satellite including the coordinates and time of an external trigger from another payload, and distributes them to two telescopes. These functions are implemented in field programmable gates arrays (FPGA) for low power consumption and fast processing without a microprocessor. The UDAQ architecture, control of the system, and data flow will be presented., Comment: 4 pages, 7 figures, 2 tables, proceeding paper for the 32nd International Conference on Cosmic Rays (ICRC), Beijing, August 11-18, 2011

The Ultra-Fast Flash Observatory (UFFO) pathfinder is a space mission devoted to the measurement of Gamma-Ray Bursts (GRBs), especially their early light curves which will give crucial information on the progenitor stars and central engines of the GRBs. It consists of two instruments: the UFFO Burst Alert & Trigger telescope (UBAT) for the detection of GRB locations and the Slewing Mirror Telescope (SMT) for the UV/optical afterglow observations, upon triggering by UBAT. The UBAT employs a coded-mask {\gamma}/X-ray camera with a wide field of view (FOV), and is comprised of three parts: a coded mask, a hopper, and a detector module (DM). The UBAT DM consists of a LYSO scintillator crystal array, multi-anode photo multipliers, and analog and digital readout electronics. We present here the design and fabrication of the UBAT DM, as well as its preliminary test results., Comment: 4 pages, 7 figures, 3 tables, ICRC conference proceeding paper; Beijing, August 11-18, 2011

The Ultra-Fast Flash Observatory (UFFO) is a new space-based experiment to observe Gamma-Ray Bursts (GRBs). GRBs are the most luminous electromagnetic events in the universe and occur randomly in any direction. Therefore the UFFO consists of two telescopes; UFFO Burst Alert & Trigger Telescope (UBAT) to detect GRBs using a wide field-of-view (FOV), and a Slewing Mirror Telescope (SMT) to observe UV/optical events rapidly within the narrow, targeted FOV. The SMT is a Ritchey-Chretien telescope that uses a motorized mirror system and an Intensified Charge-Coupled Device (ICCD). When the GRB is triggered by the UBAT, the SMT receives the position information and rapidly tilts the mirror to the target. The ICCD start to take the data within a second after GRB is triggered. Here we give the details about the SMT readout electronics that deliver the data.

The Ultra-Fast Flash Observatory (UFFO) pathfinder is a space mission devoted to the measurement of Gamma-Ray Bursts (GRBs), especially their early light curves which will give crucial information on the progenitor stars and central engines of the GRBs. It consists of two instruments: the UFFO Burst Alert & Trigger telescope (UBAT) for the detection of GRB locations and the Slewing Mirror Telescope (SMT) for the UV/optical afterglow observations, upon triggering by UBAT. The UBAT employs a coded-mask {\gamma}/X-ray camera with a wide field of view (FOV), and is comprised of three parts: a coded mask, a hopper, and a detector module (DM). The UBAT DM consists of a LYSO scintillator crystal array, multi-anode photo multipliers, and analog and digital readout electronics. We present here the design and fabrication of the UBAT DM, as well as its preliminary test results.

The Ultra-Fast Flash Observatory (UFFO) pathfinder is a space mission devoted to the measurement of Gamma-Ray Bursts (GRBs), especially their early light curves which will give crucial information on the progenitor stars and central engines of the GRBs. It consists of two instruments: the UFFO Burst Alert & Trigger telescope (UBAT) for the detection of GRB locations and the Slewing Mirror Telescope (SMT) for the UV/optical afterglow observations, upon triggering by UBAT. The UBAT employs a coded-mask {\gamma}/X-ray camera with a wide field of view (FOV), and is comprised of three parts: a coded mask, a hopper, and a detector module (DM). The UBAT DM consists of a LYSO scintillator crystal array, multi-anode photo multipliers, and analog and digital readout electronics. We present here the design and fabrication of the UBAT DM, as well as its preliminary test results.

The Ultra-Fast Flash Observatory-Pathfinder (UFFO-P) is to be launched onboard Lomonosov spacecraft in November 2011. It is to measure early UV/Optical photons from Gamma Ray Bursts (GRBs). Slewing Mirror Telescope (SMT) is one of two instruments designed for detection of UV/Optical images of the GRBs. SMT is a Ritchey-Chr\'etien telescope of 100 mm in diameter with a motorized slewing mirror at the entrance providing 17\times17 arcmin2 in Field of View (FOV) and 4 arcsec in pixel resolution. Its sky coverage can be further expanded up to 35 degrees in FOV by tilting a motorized slewing mirror. All mirrors were fabricated to about RMS 0.02 waves in wave front error (WFE) and 84.7% (in average reflectivity) over 200nm~650nm range. SMT was aligned to RMS 0.05 waves in WFE (test wavelength 632.8nm). From the static gravity test result, SMT optics system is expected to survive during launch. The technical details of SMT assembly and laboratory performance test results are reported., Comment: 4 pages, 6 figures, proceeding paper for the 32nd International Conference on Cosmic Rays (ICRC), Beijing, August 11-18, 2011

The Ultra-Fast Flash Observatory (UFFO) is a new space-based experiment to observe Gamma-Ray Bursts (GRBs). GRBs are the most luminous electromagnetic events in the universe and occur randomly in any direction. Therefore the UFFO consists of two telescopes; UFFO Burst Alert & Trigger Telescope (UBAT) to detect GRBs using a wide field-of-view (FOV), and a Slewing Mirror Telescope (SMT) to observe UV/optical events rapidly within the narrow, targeted FOV. The SMT is a Ritchey-Chretien telescope that uses a motorized mirror system and an Intensified Charge-Coupled Device (ICCD). When the GRB is triggered by the UBAT, the SMT receives the position information and rapidly tilts the mirror to the target. The ICCD start to take the data within a second after GRB is triggered. Here we give the details about the SMT readout electronics that deliver the data.

Hundreds of gamma-ray burst (GRB) optical light curves have been measured since the discovery of optical afterglows. However, even after nearly 7 years of operation of the Swift Observatory, only a handful of measurements have been made soon (within a minute) after the gamma ray signal. This lack of early observations fails to address burst physics at short time scales associated with prompt emissions and progenitors. Because of this lack of sub-minute data, the characteristics of the rise phase of optical light curve of short-hard type GRB and rapid-rising GRB, which may account for ~30% of all GRB, remain practically unknown. We have developed methods for reaching sub-minute and sub-second timescales in a small spacecraft observatory. Rather than slewing the entire spacecraft to aim the optical instrument at the GRB position, we use rapidly moving mirror to redirect our optical beam. As a first step, we employ motorized slewing mirror telescope (SMT), which can point to the event within 1s, in the UFFO Pathfinder GRB Telescope onboard the Lomonosov satellite to be launched in Nov. 2011. UFFO's sub-minute measurements of the optical emission of dozens of GRB each year will result in a more rigorous test of current internal shock models, probe the extremes of bulk Lorentz factors, provide the first early and detailed measurements of fast-rise GRB optical light curves, and help verify the prospect of GRB as a new standard candle. We will describe the science and the mission of the current UFFO Pathfinder project, and our plan of a full-scale UFFO-100 as the next step., Comment: 4 pages, 5 figures, to appear in the 32nd International Conference on Cosmic Rays (ICRC), Beijing, August 11-18, 2011

The Ultra-Fast Flash Observatory (UFFO) pathfinder is a space mission devoted to the measurement of Gamma-Ray Bursts (GRBs), especially their early light curves which will give crucial information on the progenitor stars and central engines of the GRBs. It consists of two instruments: the UFFO Burst Alert & Trigger telescope (UBAT) for the detection of GRB locations and the Slewing Mirror Telescope (SMT) for the UV/optical afterglow observations, upon triggering by UBAT. The UBAT employs a coded-mask {\gamma}/X-ray camera with a wide field of view (FOV), and is comprised of three parts: a coded mask, a hopper, and a detector module (DM). The UBAT DM consists of a LYSO scintillator crystal array, multi-anode photo multipliers, and analog and digital readout electronics. We present here the design and fabrication of the UBAT DM, as well as its preliminary test results., Comment: 4 pages, 7 figures, 3 tables, ICRC conference proceeding paper; Beijing, August 11-18, 2011

The Ultra-Fast Flash Observatory (UFFO) Pathfinder is a payload on the Russian Lomonosov satellite, scheduled to be launched in November 2011. The Observatory is designed to detect early UV/Optical photons from Gamma-Ray Bursts (GRBs). There are two telescopes and one main data acquisition system: the UFFO Burst Alert & Trigger Telescope (UBAT), the Slewing Mirror Telescope (SMT), and the UFFO Data Acquisition (UDAQ) system. The UDAQ controls and manages the operation and communication of each telescope, and is also in charge of the interface with the satellite. It will write the data taken by each telescope to the NOR flash memory and sends them to the satellite via the Bus-Interface system (BI). It also receives data from the satellite including the coordinates and time of an external trigger from another payload, and distributes them to two telescopes. These functions are implemented in field programmable gates arrays (FPGA) for low power consumption and fast processing without a microprocessor. The UDAQ architecture, control of the system, and data flow will be presented., Comment: 4 pages, 7 figures, 2 tables, proceeding paper for the 32nd International Conference on Cosmic Rays (ICRC), Beijing, August 11-18, 2011