Implicit Models of School Improvement: A Mixed Method Analysis

There is a persistent belief that public schools are profoundly in need of improvement (Berliner & Biddle, 1995). Given substantial research on teaching literature (Borman, Hewes, Overman, & Brown, 2003; Hertling, 2000), it is not clear why more progress has not been made. Perhaps an answer may be found in the complexity of the educational literature, which provides a confused map toward accomplishing school improvement. Educational leaders are left in the position of relying on either imprecisely formulated or idiosyncratic and implicit models of school improvement without clear guidelines to follow for specific contexts. Models appear as ex post facto, reflecting an approach to educational reform on the part of administrators that may be best thought of as implicit

The timing of the deglaciation in the Atlantic Iberian mountains:Insights from the stratigraphic analysis of a lake sequence in Serra da Estrela (Portugal)

Understanding the environmental response to the last glacial termination in regions located in transitional climate zones such as the Atlantic Iberian mountains is crucial to estimate potential changes in regions affected by current glacial melting. We present an 8.5 m-long, solid last deglaciation and Holocene chronostratigraphic record including detailed sediment analysis from Lake Peixão, a pro-glacial lake in the Serra da Estrela (Central Portugal). The age–depth model relies on a Bayesian approach that includes 16 AMS 14C dates and 210Pb–137CS measurements, robustly dating the lake formation at 14.7 ± 0.32 cal. ka BP. This chronological reconstruction shows an average sedimentation rate of ca. 0.07 cm yr−1 (15 yr cm−1), enabling proxy analyses at decadal timescales. The sediment sequence is composed of five lithological units: (U1) coarse and unsorted fluvioglacial lacustrine deposits; (U2) massive fluvioglacial lacustrine deposits (863–790 cm below surface [bsf]; 14.7 ± 0.32–13.8 ± 0.12 cal. ka BP); (U3) water current fluvioglacial lacustrine deposits (790–766 cm bsf; 13.8 ± 0.12–12.9 ± 0.29 cal. ka BP); (U4) laminated/banded lacustrine deposits characterized by terrigenous deposits from ice-covered lake periods and episodic events of ice and snow melting (766–752 cm bsf; 12.9 ± 0.29–11.7 ± 0.15 cal. ka BP); and (U5) massive muddy lacustrine deposits (752–0 cm bsf; 11.7 ± 0.15 cal. ka BP–present). The occurrence of U2 to U4 deposits defines the transition from glacial cold (U1) to net warm postglacial conditions (U5). These climate transitions are marked by changes in sediments and the presence of very low sedimentation rate periods, possibly related to the Intra-Allerød Cold Period and the coldest phase of the Younger Dryas. Our results support the previously proposed timing of the retreat of the Serra da Estrela glaciers ca. 13.8 ± 0.12 cal. ka BP. The robust chronology of Lake Peixão highlights the potential of Iberian pro-glacial lakes for dating deglaciation processes and will lead to unprecedented decadal-to-centennial timescale palaeoclimate reconstructions in this region since the last glacial–interglacial transition

The timing of the deglaciation in the Atlantic Iberian mountains: Insights from the stratigraphic analysis of a lake sequence in Serra da Estrela (Portugal)

Understanding the environmental response to the last glacial termination in regions located in transitional climate zones such as the Atlantic Iberian mountains is crucial to estimate potential changes in regions affected by current glacial melting. We present an 8.5 m-long, solid last deglaciation and Holocene chronostratigraphic record including detailed sediment analysis from Lake Peixao, a pro-glacial lake in the Serra da Estrela (Central Portugal). The age-depth model relies on a Bayesian approach that includes 16 AMS C-14 dates and Pb-210-(CS)-C-137 measurements, robustly dating the lake formation at 14.7 +/- 0.32 cal. ka BP. This chronological reconstruction shows an average sedimentation rate of ca. 0.07 cm yr(-1) (15 yr cm(-1)), enabling proxy analyses at decadal timescales. The sediment sequence is composed of five lithological units: (U1) coarse and unsorted fluvioglacial lacustrine deposits; (U2) massive fluvioglacial lacustrine deposits (863-790 cm below surface [bsf]; 14.7 +/- 0.32-13.8 +/- 0.12 cal. ka BP); (U3) water current fluvioglacial lacustrine deposits (790-766 cm bsf; 13.8 +/- 0.12-12.9 +/- 0.29 cal. ka BP); (U4) laminated/banded lacustrine deposits characterized by terrigenous deposits from ice-covered lake periods and episodic events of ice and snow melting (766-752 cm bsf; 12.9 +/- 0.29-11.7 +/- 0.15 cal. ka BP); and (U5) massive muddy lacustrine deposits (752-0 cm bsf; 11.7 +/- 0.15 cal. ka BP-present). The occurrence of U2 to U4 deposits defines the transition from glacial cold (U1) to net warm postglacial conditions (U5). These climate transitions are marked by changes in sediments and the presence of very low sedimentation rate periods, possibly related to the Intra-Allerod Cold Period and the coldest phase of the Younger Dryas. Our results support the previously proposed timing of the retreat of the Serra da Estrela glaciers ca. 13.8 +/- 0.12 cal. ka BP. The robust chronology of Lake Peixao highlights the potential of Iberian pro-glacial lakes for dating deglaciation processes and will lead to unprecedented decadal-to-centennial timescale palaeoclimate reconstructions in this region since the last glacial-interglacial transition.info:eu-repo/semantics/publishedVersio

The timing of the deglaciation in the Atlantic Iberian mountains: Insights from the stratigraphic analysis of a lake sequence in Serra da Estrela (Portugal)

Understanding the environmental response to the last glacial termination in regions located in transitional climate zones such as the Atlantic Iberian mountains is crucial to estimate potential changes in regions affected by current glacial melting. We present an 8.5 m-long, solid last deglaciation and Holocene chronostratigraphic record including detailed sediment analysis from Lake Peix˜ao, a pro-glacial lake in the Serra da Estrela (Central Portugal). The age–depth model relies on a Bayesian approach that includes 16 AMS 14C dates and 210Pb–137CS measurements, robustly dating the lake formation at 14.7 ± 0.32 cal. ka BP. This chronological reconstruction shows an average sedimentation rate of ca. 0.07 cm yr 1 (15 yr cm 1), enabling proxy analyses at decadal timescales. The sediment sequence is composed of five lithological units: (U1) coarse and unsorted fluvioglacial lacustrine deposits; (U2) massive fluvioglacial lacustrine deposits (863–790 cm below surface [bsf]; 14.7 ± 0.32–13.8 ± 0.12 cal. ka BP); (U3) water current fluvioglacial lacustrine deposits (790–766 cm bsf; 13.8 ± 0.12–12.9 ± 0.29 cal. ka BP); (U4) laminated/banded lacustrine deposits characterized by terrigenous deposits from ice-covered lake periods and episodic events of ice and snow melting (766–752 cm bsf; 12.9 ± 0.29–11.7 ± 0.15 cal. ka BP); and (U5) massive muddy lacustrine deposits (752–0 cm bsf; 11.7 ± 0.15 cal. ka BP–present). The occurrence of U2 to U4 deposits defines the transition from glacial cold (U1) to net warm postglacial conditions (U5). These climate transitions are marked by changes in sediments and the presence of very low sedimentation rate periods, possibly related to the Intra-Allerød Cold Period and the coldest phase of the Younger Dryas. Our results support the previously proposed timing of the retreat of the Serra da Estrela glaciers ca. 13.8 ± 0.12 cal. ka BP. The robust chronology of Lake Peix˜ao highlights the potential of Iberian pro-glacial lakes for dating deglaciation processes and will lead to unprecedented decadal-to-centennial timescale palaeoclimate reconstructions in this region since the last glacial–interglacial transition.info:eu-repo/semantics/publishedVersio

The timing of the deglaciation in the Atlantic Iberian mountains: Insights from the stratigraphic analysis of a lake sequence in Serra da Estrela (Portugal).

Understanding the environmental response to the last glacial termination in regions located in transitional climate zones such as the Atlantic Iberian mountains is crucial to estimate potential changes in regions affected by current glacial melting. We present an 8.5 m-long, solid last deglaciation and Holocene chronostratigraphic record including detailed sediment analysis from Lake Peix¿ao, a pro-glacial lake in the Serra da Estrela (Central Portugal). The age-depth model relies on a Bayesian approach that includes 16 AMS 14C dates and 210Pb-137CS measurements, robustly dating the lake formation at 14.7 ± 0.32 cal. ka BP. This chronological reconstruction shows an average sedimentation rate of ca. 0.07 cm yr-1 (15 yr cm-1), enabling proxy analyses at decadal timescales. The sediment sequence is composed of five lithological units: (U1) coarse and unsorted fluvioglacial lacustrine deposits; (U2) massive fluvioglacial lacustrine deposits (863-790 cm below surface [bsf]; 14.7 ± 0.32-13.8 ± 0.12 cal. ka BP); (U3) water current fluvioglacial lacustrine deposits (790-766 cm bsf; 13.8 ± 0.12-12.9 ± 0.29 cal. ka BP); (U4) laminated/banded lacustrine deposits characterized by terrigenous deposits from ice-covered lake periods and episodic events of iceand snow melting (766-752 cm bsf; 12.9 ± 0.29-11.7 ± 0.15 cal. ka BP); and (U5) massive muddy lacustrine deposits (752-0 cm bsf; 11.7 ± 0.15 cal. ka BP-present). The occurrence of U2 to U4 deposits defines the transition from glacial cold (U1) to net warm postglacial conditions (U5). These climate transitions are marked bychanges in sediments and the presence of very low sedimentation rate periods, possibly related to the Intra-Allerød Cold Period and the coldest phase of the Younger Dryas. Our results support the previously proposed timing of the retreat of the Serra da Estrela glaciers ca. 13.8 ± 0.12 cal. ka BP. The robust chronology of Lake Peixao highlights the potential of Iberian pro-glacial lakes for dating deglaciation processes and will lead to unprecedented decadal-to-centennial timescale palaeoclimate reconstructions in this region since the last glacial-interglacial transition

A 4,000 YEAR LAKE SEDIMENT RECORD OF ATMOSPHERIC LEAD POLLUTION FROM NORTHWESTERN SPAIN

The Iberian Peninsula is rich in mineral resources that have been repeatedly exploited for hundreds, and sometimes thousands of years, leaving a legacy of metal pollution in the environment. This study presents a c. 4,000-year lake sediment record of atmospheric lead (Pb) deposition from Laguna Roya (42° 8'8.42"N, 6°47'38.95"E), a small glacial lake located in the Sierra Segundera of northwestern Spain. A chronological profile of Pb accumulation was reconstructed using the Pb concentration ([Pb]) and 206Pb/207Pb isotope ratios to elucidate the regional lead pollution history. Anthropogenic lead emissions are indicated after c. 500 BC, when 206Pb/207Pb ratios begin to decrease and [Pb] begins to increase. There is an abrupt maximum [Pb] peak (63 ppm), and minimum 206Pb/207Pb= 1.1760 that occurs c. 15 BC, prior to the Roman occupation of the region. After the Fall of Rome (c. 550 AD), [Pb] decreases to 15 ppm. The 206Pb/207Pb increases to c. 1.1858 and remains relatively constant until just prior to the Industrial Revolution (c. 1820 AD) when atmospheric Pb deposition begins to steadily increase again. The [Pb] reaches a maximum (39 ppm) in 1972 AD and 206Pb/207Pb reaches a minimum (1.1688) in 1995 AD. Source attribution of the anthropogenic Pb was estimated and compared to published lead isotope values of ores associated with mining sites throughout the Iberian Peninsula. It was found that the sources of atmospheric lead pollution prior to 1700 AD are ore deposits from the northwest of the peninsula. From 1700 AD until the mid-20th century the primary Pb emission sources are ores from the southwestern Iberian Pyrite Belt and the south-central Linares-La Carolina mining districts. After 1960, leaded gasoline became a primary lead pollution source. It is estimated, that in 1972, 29% of the atmospheric Pb deposited in Laguna Roya was from leaded gasoline and 52% was from the southwestern and south-central ore fields. The Pb pollution record in Laguna Roya sediments not only illustrates the persistence and pervasiveness of lead pollution throughout history, but it also demonstrates how Pb concentrations and isotopic signatures in sediment archives reflect changes in both industrial activities, and trade relations throughout history

Lead isotope fingerprinting techniques help identify and quantify 3,000 years of atmospheric lead pollution from Laguna Roya, northwestern Iberia Supplemental

Until ~1960 CE the primary source of anthropogenic Pb in the Laguna Roya sediment record was atmospheric Pb pollution from distant, largescale metal refining in the SW.Dated slag Pb isotope ratios from the Rio Tinto mining district provided strong evidence to identify the source of Pb pollution in Laguna Roya sediments. The primary source of lake sediment Pb pollution after 1960 CE is metal processing from the SW mining district (~85%) whereas leaded gasoline contributes ~15%

Public School Absenteeism and the Impact of COVID-19

The impact of regular school attendance is invaluable for students, especially at-risk children. COVID 19 has presented many challenges for students, including absenteeism. Today, many public schools ask that students stay home when ill or test positive for COVID 19. Although this is important for the health and safety of students, it has also sent mixed messages to some families, especially those that previously struggled to attend school regularly. Absenteeism is rising; research has shown it negatively impacts academic success. More than ever, schools need to take steps to combat absenteeism and help students and their families see education in a positive light. This project aims to review literature related to absenteeism, find common themes to improve student attendance, and develop a small group intervention system that can be used at the elementary level to increase student attendance