Persistence. Despite challenges, the team persists in working toward the goals included in the wraparound plan until such time as the family has met their goals and/or are no longer requesting assistance from the ISST.
Persistence. We wish to allow theories in which the binding to up hold rights is either one shot i e may only be exercised once or persistent for the duration of the commitment i e may be exercised an unlimited number of times while the agent is bound to uphold the agreement in which it is permitted Axioms and respectively express these two alternatives A Bound x Agree Right y z a Done y a
Persistence. Teacher persists in seeking effective approaches for students who need help, using an extensive repertoire of strategies and soliciting additional resources for the school.
Persistence. All degradation results show that PFOA is persistent and does not undergo any abiotic or biotic degradation under relevant environmental conditions. According to Xxxxx XXXX (section 1.1.1), PFOA meets the criteria for being persistent (P) and very persistent (vP).
Persistence. Based on the available information from experimental and estimated data, CHR degrades very slowly in soil with half-lives of >180 d. Thus, the P and the vP criteria of REACH Annex XIII are fulfilled.
Persistence. The Member State Committee in its opinion3 concluded that: With regard to the assessment of persistence, MSC concludes that the experimental observations in simulation and monitoring studies lead to the conclusion that both D4 and D5 meet the vP criterion as specified in REACH Annex XIII. MSC has evaluated non-degradation processes and concluded that these do not have a large impact on the sediment removal half-life, and thus cannot be used to refute the relevance of the sediment compartment in the assessment of persistence. […] Based on OECD TG 308 sediment simulation studies (Xx, 2010), D5 has a degradation half- life in freshwater sediment of the order of 800-3,100 days at 24°C. MSC concludes that D5 meets the Annex XIII criteria for a very persistent (vP) substance in sediment according to Regulation (EC) No 1907/2006. After the MSC and RAC opinion making processes, new studies have been published. The relevant studies have been summarised in the Support document to this agreement. This new information supports the earlier conclusion. Bioaccumulation The Member State Committee in its opinion3 concluded that: 2 ECHA (2015): Member State Committee’s Opinion on Persistency and bioaccumulation of Octamethylcyclotetrasiloxane (D4) (EC No: 000-000-0, CAS No: 556-67-2) and Decamethylcyclopentasiloxane (D5) (EC No. 000-000-0, CAS No. 541- 02-6). xxxxx://xxxx.xxxxxx.xx/about-us/who-we-are/member-state-committee/opinions-of-the-msc-adopted-under- specific-echa-s-executive-director-requests 4 The restriction on D4 and D5 entered into force in 31.1.2018 (European Commssion, 2018): xxxx://xxx- xxx.xxxxxx.xx/xxxxx-xxxxxxx/XX/XXX/?xxx=xxxxxxx:XX.X_.0000.000.00.0000.00.XXX With regard to the assessment of bioaccumulation, MSC concludes that D4 and D5 are very bioaccumulative based on high fish BCF values, supported by multiple lines of evidence on biomagnification in dietary studies, and elimination half-lives. In addition, the available field data provides evidence that bioaccumulation and trophic magnification have been shown to occur in certain food webs in the environment. The available information on biomagnification and trophic magnification factors (BMF/TMF) in the field, indicating that biodilution occurs in some food chains or in parts of some food chains, does not invalidate the other lines of evidence. […] D5 meets the Annex XIII criteria for a very bioaccumulative (vB) substance according to Regulation (EC) No 1907/2006 based on the following studies: • A ...
Persistence. For the persistence assessment of terphenyl, hydrogenated, most weight is given to half- lives measured in standard simulation tests or simulation tests which are considered comparable to standard tests in terms of reliability and test conditions. Half-lives from such tests can be directly compared with the P/vP criteria. Results from simulation tests with conditions differing from standard tests (or with insufficient documentation), screening tests, QSAR predictions, and microbial culture studies, are used as supporting information. Based on the weight-of-evidence assessment of available relevant information, terphenyl, hydrogenated fulfils the P and vP criteria. The relevant findings are summarised below: - Based on available information, abiotic degradation is expected to occur at such a low rate that it is not considered a relevant route of degradation for P/vP assessment - In a soil simulation test, dissipation half-lives in soil of ≥218 days (temperature-corrected to 12°C) were determined for terphenyl and >224 days quaterphenyl (Monsanto Company 1989) thus fulfilling the P and vP criteria. These half-lives were determined for a mixture of terphenyls, quaterphenyls, and polyphenyls (the proportions of the different isomers are not known). Quaterphenyls and terphenyls are relevant constituents of the UVCB substance. - In a seawater simulation test with hydrocarbon mixtures (ExxonMobil Biomedical Science, Inc., 2009) primary degradation half-live (temperature- corrected to 12°C) of >182 days was reported for o-terphenyl and half-lives of 32 d and 108 d for m-terphenyl, suggesting that o-terphenyl and m-terphenyl fulfil the P/vP criterion in marine water. - In an OECD 307 soil simulation test a dissipation half-life of 2-10 days (NOTOX 2009) for p-dicyclohexylbenzene (HT2) was detected during the test when the half-lifes are calculated for the whole test duration using bi-phasic models. Assuming that all non-extractable residues (NER) are parent substance, the half- life is 6-18 days in two soils whereas for one soil no exact half-life can be determined and it is estimated that the half-life for this soil is above test duration, i.e., >120 days. When the second phase (‘slow phase’) from bi-phasic models is used the half-lives were 38-46 days in one soil (with possible underestimation as the kinetic fit was not optimal), 185 days in one soil (with uncertainty as the k2 parameter was not statistically significant and as the half-life obtained from tempera...
Persistence. The screening criterion for persistence (P) is fulfilled for 5-sec-butyl-2-(2,4- dimethylcyclohex-3-en-1-yl)-5-methyl-1,3-dioxane [1], 5-sec-butyl-2-(4,6- dimethylcyclohex-3-en-1-yl)-5-methyl-1,3-dioxane [2] [covering any of the individual stereoisomers of [1] and [2] or any combination thereof]. The results from three biodegradation studies showed that the substance is neither readily, nor inherently biodegradable. Hydrolysis of this substance was shown to be at most very limited at environmentally relevant pH and temperature values. In a river water die-away test, the proposed substance degraded very slowly. This study was conducted with non-radio labelled substance. A best-case degradation half-life was estimated by attributing the observed dissipation to either biodegradation or hydrolysis, disregarding processes such as evaporation and binding of the substance. At an environmentally relevant temperature of 12°C this best-case degradation half-life corresponded to 74 days. Therefore, as the vP criterion of 60 days in freshwater is exceeded, the substance 5-sec-butyl-2-(2,4- dimethylcyclohex-3-en-1-yl)-5-methyl-1,3-dioxane [1], 5-sec-butyl-2-(4,6- dimethylcyclohex-3-en-1-yl)-5-methyl-1,3-dioxane [2] [covering any of the individual stereoisomers of [1] and [2] or any combination thereof] is regarded as fulfilling both the P and vP criterion.
Persistence. Table 1 represents the persistence rates for RVC students overall and disaggregated by demographic subgroups, including enrollment status (full time or part time), gender, race/ethnicity, and age (traditional or nontraditional). Table 1: RVC Student Persistence Rates by Various Demographic Groups (Fall-to-Spring - %) Fiscal Year: FY12 (Fall 2011) FY13 (Fall 2012) FY14 (Fall 2013) FY15 (Fall 2014) FY16 (Fall 2015) Rate of change (FY12-FY16) Overall 73.9 73.1 72.7 72.9 72.7 -1.6% Status1 Full time 86.8 87.7 86.2 86.6 87.2 0.6% Part time 63.7 62.9 62.2 62.7 62.0 -2.7% Gender Male 73.0 73.5 73.0 72.7 71.8 -1.6% Female 74.6 72.9 72.4 73.1 73.4 -1.6% Race/Ethnicity American Indian / Alaska Native 71.7 77.8 65.3 83.6 62.2 -13.2% Asian 75.7 77.3 76.8 78.4 72.3 -4.5% Black / African American 65.8 62.9 60.3 62.2 56.9 -13.5% Hispanic / Latino 71.8 76.2 75.3 73.9 72.2 0.6% Native Hawaiian / Other Pacific Islander * * * * * * White 75.1 73.6 73.7 73.7 74.8 -0.4% Age2 Traditional 75.9 75.8 75.5 74.9 75.6 -0.4% Nontraditional 70.4 68.2 66.7 68.2 65.6 -6.8% Source: Office of Institutional Research Persistence Application *Percentages are not reported for group sizes of 30 or less Over the past five years, overall fall to spring persistence has decreased from 73.9% to 72.7%. Disaggregated persistence rate data in Table 1 suggest: Enrollment Status • Full-time students consistently persist at a higher rate than part-time students. • Over the five-year period reported, persistence rates decreased for part-time students, while persistence rates for full-time students remained relatively stable. Gender - Both male and female persistence rates demonstrated an overall decrease from FY2012 to FY2016. Race/Ethnicity • Black/African American students consistently persist at a lower rate than their peers in all other racial/ethnic groups. The persistence rate of Black/African American students decreased over the five-year period reported, widening the achievement gap between black and white students. • The persistence rate of Hispanic/Latino students has remained stable over the five-year period. The achievement gap between Hispanic/Latino and white students has generally narrowed. 1 Full-time students are enrolled in 12 credits or more, and part-time students are enrolled in less than 12 credit hours.
Persistence. PFHxS has a stable perfluorinated structure and is not expected to undergo abiotic degradation under relevant environmental conditions. An available photo- transformation study in water, which found negligible degradation via photolysis, supports this understanding. There is no study available on biodegradation, so data from structurally similar compounds are therefore used in a read-across approach. A read-across with PFOS is applied for biodegradation screening test and a read-across with PFOS and PFOA is applied for the simulation tests (in water, sediment and soil). The persistence of PFSAs and PFCAs can, in general, be explained by the shielding effect of the fluorine atoms, blocking e.g. nucleophilic attacks on the carbon chain. High electronegativity, low polarisability and high bond energies make highly fluorinated alkanes extremely stable organic compounds. It is not expected that the sulphonic group in PFSAs alters the persistence of these chemicals. The persistence of PFOS and the eight entries of PFCAs included into the Candidate List has already been confirmed. Therefore, based on the knowledge of the stability of the X-X xxxx and the read- across approach with PFOS and PFOA, it is concluded that PFHxS is expected to undergo extremely limited degradation in the environment and thus fulfils the persistent (P-) and very persistent (vP) criteria in accordance with the criteria and provisions set out in Annex XIII of REACH.
