Donor sibling relations among adult offspring conceived via insemination by lesbian parents.

STUDY QUESTION: How do adult offspring in planned lesbian-parent families feel about and relate to their donor (half) sibling(s) (DS)? SUMMARY ANSWER: A majority of offspring had found DS and maintained good ongoing relationships, and all offspring (regardless of whether a DS had been identified) were satisfied with their knowledge of and contact level with the DS. WHAT IS KNOWN ALREADY: The first generation of donor insemination offspring of intended lesbian-parent families is now in their 30s. Coincident with this is an increased use of DNA testing and genetic ancestry websites, facilitating the discovery of donor siblings from a common sperm donor. Few studies of offspring and their DS include sexual minority parent (SMP) families, and only sparse data separately analyze the offspring of SMP families or extend the analyses to established adult offspring. STUDY DESIGN, SIZE, DURATION: This cohort study included 75 adult offspring, longitudinally followed since conception in lesbian-parent families. Quantitative analyses were performed from online surveys of the offspring in the seventh wave of the 36-year study, with a 90% family retention rate. The data were collected from March 2021 to November 2022. PARTICIPANTS/MATERIALS, SETTING, METHODS: Participants were 30- to 33-year-old donor insemination offspring whose lesbian parents enrolled in a US prospective longitudinal study when these offspring were conceived. Offspring who knew of a DS were asked about their numbers found, characteristics or motivations for meeting, DS terminology, relationship quality and maintenance, and impact of the DS contact on others. All offspring (with or without known DS) were asked about the importance of knowing if they have DS and their terminology, satisfaction with information about DS, and feelings about future contact. MAIN RESULTS AND THE ROLE OF CHANCE: Of offspring, 53% (n = 40) had found DS in modest numbers, via a DS or sperm bank registry in 45% of cases, and most of these offspring had made contact. The offspring had their meeting motivations fulfilled, viewed the DS as acquaintances more often than siblings or friends, and maintained good relationships via meetings, social media, and cell phone communication. They disclosed their DS meetings to most relatives with neutral impact. The offspring, whether with known or unknown DS, felt neutral about the importance of knowing if they had DS, were satisfied with what they knew (or did not know) of the DS, and were satisfied with their current level of DS contact. This study is the largest, longest-running longitudinal study of intended lesbian-parent families and their offspring, and due to its prospective nature, is not biased by over-sampling offspring who were already satisfied with their DS. LIMITATIONS, REASONS FOR CAUTION: The sample was from the USA, and mostly White, highly educated individuals, not representative of the diversity of donor insemination offspring of lesbian-parent families. WIDER IMPLICATIONS OF THE FINDINGS: While about half of the offspring found out about DS, the other half did not. Regardless of knowing of a DS, these adult offspring of lesbian parents were satisfied with their level of DS contact. Early disclosure and identity formation about being donor-conceived in a lesbian-parent family may distinguish these study participants from donor insemination offspring and adoptees in the general population, who may be more compelled to seek genetic relatives. The study participants who sought DS mostly found a modest number of them, in contrast to reports in studies that have found large numbers of DS. This may be because one-third of study offspring had donors known to the families since conception, who may have been less likely to participate in commercial sperm banking or internet donation sites, where quotas are difficult to enforce or nonexistent. The study results have implications for anyone considering gamete donation, gamete donors, donor-conceived offspring, and/or gamete banks, as well as the medical and public policy professionals who advise them. STUDY FUNDING/COMPETING INTEREST(S): No funding was provided for this project. The authors have no competing interests. TRIAL REGISTRATION NUMBER: N/A.

Sperm donor relations among adult offspring conceived via insemination by lesbian parents.

AIM: The present study examined how adult offspring of lesbian parents relate to their anonymous, open-identity, or known donors. DESIGN: An online survey of 75 donor-conceived offspring of lesbian parents, aged 30-33 years, participating in Wave 7 of a U.S. 36-year longitudinal study of planned lesbian-parent families was conducted. Offspring were asked about donor type, motivations for contacting the donor, terminology for the donor, relationship quality, means of relationship maintenance, impact of donor contact on offspring's other family members, and their feelings about the donor. RESULTS: Twenty offspring with anonymous donors and 15 with open-identity donors whom they had not contacted felt comfortable not knowing their donors. Forty offspring knew their donors - anonymous, contacted through an online registry (n = 7), open-identity, contacted (n = 9), or known since childhood (n = 24). Offspring who had contacted their donor since age 18 had their motivations fulfilled after contact, got along well with him, did not view him as a relative, and had told most family members about their contact, without detriment. Whether the donor was unknown or known at this stage of their lives, most offspring were satisfied with their contact level. CONCLUSION: This cohort of donor-conceived offspring of lesbian parents was among the first to reach adulthood during a time of technological advances in DNA testing, giving access to anonymous donors via online registries. The results inform donors, families, mental health providers, medical providers and public policymakers, on whether, how, and to what degree donor-conceived offspring optimally make donor contact.

Adapting ENABLE for patients with advanced cancer and their family caregivers in Singapore: a qualitative formative evaluation.

BACKGROUND: ENABLE (Educate, Nurture, Advise, Before Life Ends) is a nurse coach-led, early palliative care model for patients with advanced cancer and their family caregivers. Content covered includes problem-solving, advance care planning, symptom management and self-care. The aim was to evaluate the cultural acceptability of ENABLE among patients with advanced cancer and their caregivers in Singapore and identify modifications for an adapted ENABLE-SG model. METHODS: Qualitative formative evaluation with a thematic analysis approach in two hospitals in Singapore, involving patients (n = 10), family caregivers (n = 11) and healthcare professionals (n = 10) who care for patients with advanced cancer. Semi-structured interviews were conducted to explore (i) the main needs and challenges facing individuals with advanced cancer and their family caregivers; (ii) patient involvement in healthcare decision making; and (iii) content and delivery of ENABLE. RESULTS: While physical needs were largely well met, participants expressed that psychosocial care was delivered too late in the illness trajectory. Healthcare decision making approaches varied from a patient-centred shared decision-making model to a family-centred model where patients may not know their cancer diagnosis and prognosis. The content was considered to be relevant, comprehensive and practical; financial assistance, adjustment to body image, and evaluation of complementary therapy were also recommended. Face-to-face rather than telephone sessions were preferred to facilitate rapport building. CONCLUSIONS: ENABLE was broadly acceptable with some modifications, including adjusting the content to ensure it can be delivered even if the patient is not fully aware of cancer diagnosis and delivering the first session face-to-face with flexibility for subsequent sessions.

Long-Term Effects of Homophobic Stigmatization During Adolescence on Problem Behavior in Emerging Adult Offspring of Lesbian Parents.

The long-term impact of homophobic stigmatization on adolescents with lesbian parents has not been explored. This longitudinal study investigated the effects of homophobia experienced during adolescence on problem behavior among emerging adult offspring of lesbian parents. The 72 offspring (37 females and 35 males; all cisgender and 25 years old) were predominantly White, heterosexual, and highly educated. As 17-year-old adolescents, 40.3% (n = 29) reported that they had been treated unfairly because of having lesbian parents. Experienced homophobia during adolescence was indirectly associated with internalizing problems during emerging adulthood through psychological problems during adolescence and meaning in life in emerging adulthood. Adolescent experiences of homophobia were also indirectly related to externalizing problems during emerging adulthood through adolescent psychological problems, but not through meaning in life in emerging adulthood. These findings indicate that long-term effects of homophobic stigmatization during adolescence persist into adulthood. School and community interventions should include all types of families in their diversity appreciation programs.

Development and evaluation of a quality of life measurement scale in English and Chinese for family caregivers of patients with advanced cancers.

BACKGROUND: The quality of life of family caregivers of patients with advanced cancers is an important concern in oncology care. Yet, there are few suitable measurement scales available for use in Asia. This study aims to develop and evaluate a locally derived measurement scale in English and Chinese to assess the quality of life of family caregivers of patients with advanced cancers in Singapore. METHODS: Scale contents were generated from qualitative research that solicited inputs from family caregivers. Six hundred and twelve family caregivers of patients with advanced cancers were recruited, of whom 304 and 308 chose to complete the English and Chinese versions of the quality of life scale, respectively. A follow-up survey was conducted for test-retest reliability assessment. Analyses began with pooling all observations, followed by analyses stratified by language samples and ethnic groups (among English-speaking participants). RESULTS: Factor analysis identified 5 domains of quality of life. The Root Mean Square Error of Approximation was 0.041 and Comparative Fit Index was 0.948. Convergent and divergent validity of the total and domain scores were demonstrated in terms of correlation with the Brief Assessment Scale for Caregiver and its sub-scales and a measure of financial concern; known-group validity was demonstrated in terms of differences between groups defined by patient's performance status. Internal consistency (Cronbach's alpha) of the total and domain scores ranged from 0.86 to 0.93. Test-retest reliability (intraclass correlation coefficient) ranged from 0.74 to 0.89. Separate analyses of the English- and Chinese-speaking samples and ethnic groups gave similar results. CONCLUSION: A new, validated, multi-domain quality of life measurement scale for caregivers of patients with advanced cancers that is developed with inputs from family caregivers is now available in two languages. We call this the Singapore Caregiver Quality Of Life Scale (SCQOLS).

Sexual Attraction, Sexual Identity, and Same-Sex Sexual Experiences of Adult Offspring in the U.S. National Longitudinal Lesbian Family Study.

The U.S. National Longitudinal Lesbian Family Study has followed offspring with sexual minority parents from conception into adulthood. It was initiated in 1986, and it has a 92% retention rate to date. In the current investigation, the 25-year-old offspring answered questions about sexual attraction, sexual identity, and sexual experiences; their responses were compared with those of same-age adults from a population-based survey. The analytic samples consisted of 76 offspring of lesbian parents and 76 demographically matched participants from the National Survey of Family Growth. All 152 respondents were 25 years old, 48.7% were female, 90.8% identified as White, 9.2% were people of color, and all had attended at least some college. Although most respondents in each sample identified as "heterosexual or straight," compared to their matched counterparts in the population-based survey, the female and male offspring of lesbian parents were significantly more to likely to report same-sex attraction, sexual minority identity, and same-sex experience. These findings suggest that adult offspring from planned lesbian families may be more likely than their peers to demonstrate diversity in sexual attraction, identity, and expression.

Predictors of mental health in emerging adult offspring of lesbian-parent families.

Emerging adulthood is a new, distinct life stage for 18- to 29-year-olds in the United States. In the sixth wave of data collection in a longitudinal cohort study (started in 1986), predictors of mental health were examined in the emerging adult offspring within lesbian-parent parent families. The donor-conceived offspring were 25 years old. In cross-sectional analyses, we assessed whether their mental health (life satisfaction and behavioral/emotional problems) was associated with personal characteristics, family characteristics, quality of important relationships, and experiences of homophobic stigmatization. The findings revealed that the predictors of mental health in these offspring were typical of what has been previously reported on emerging adults. However, offspring who reported stigmatization because of their parents' sexual identity had higher rates of behavioral/emotional problems than those who did not.

Neglected Intrauterine Device Migration Complications: Case Reports.

This series of four cases describes unusual intrauterine device (IUD) migration complications, associated etiologic factors, and their management. Recent increases in sociopolitical and medical forces worldwide contributed to inattention to these patients with subclinical IUD complications. The international movement of patients, delays in gynecologic care due to the COVID-19 pandemic, lack of health care access, shifts away from annual examinations, and patients' lack of medical records or IUD awareness can lead to long durations of neglected IUDs and associated complications. These complications might have been avoided or minimized with regular gynecologic health care. Physicians should consider moving toward routine examinations of all IUD patients, rather than away from annual examinations as has been promulgated by some medical societies. Patient education is needed on the importance of routine monitoring of IUDs and retention of device records. Clinicians should become familiar with IUDs from around the world as well as devices no longer being prescribed, as their appearance, associated complications, and presentations may differ from locally currently available devices.

Long-Term Effects of Family Resilience on the Subjective Well-Being of Offspring in the National Longitudinal Lesbian Family Study.

The current study used a family resilience approach to investigate why some offspring of sexual minority parents thrive despite homophobic stigmatization while others do not. Specifically, the study explored the role of two specific family functioning mechanisms (i.e., during adolescence, disclosure of offspring's personal life to their parents, and family compatibility) in the association between experienced homophobic stigmatization at age 17 and subjective well-being at age 25, among 71 offspring (37 females and 34 males, all cisgender) of the National Longitudinal Lesbian Family Study (NLLFS). The results showed that, overall, the offspring reported healthy subjective well-being as emerging adults. However, among NLLFS offspring with less family compatibility as adolescents, homophobic stigmatization was related to higher scores on negative affect when they were emerging adults. Psychological counseling that supports adolescent-parent communication may help prevent the negative effect of homophobic stigmatization on the subjective well-being of offspring with sexual minority parents.

Palliative care pain control: inpatient consultation versus corounding models compared.

BACKGROUND: Compared with the current inpatient consultation model, a novel corounding model of care whereby palliative specialists round with oncology teams, increases healthcare collaboration and may improve quality of care for inpatients. Whether this translates to better pain control for patients is unexplored. OBJECTIVE: To determine whether the corounding model provides better pain control compared with the consultation model for cancer inpatients. METHODS: Cancer patients with moderate or severe pain severity during the admission were included in this observational study. Pain severity was determined using electronic records. Improvement to mild or no pain by day 3 of identification of moderate or severe pain was defined as good pain control and proportion of admissions achieving this was compared between models. RESULTS: A total of 142 and 128 admissions admitted under the consult and corounding model, respectively, had moderate or severe pain. The proportion of patients that achieved good pain control was 77.3% (99/128) and 71.8% (102/142) in the corounding and consult model, respectively. The difference in proportion of admissions achieving good pain control was significantly higher in the corounding model after adjusting for differences in baseline characteristics (unadjusted OR, 1.34; 95% CI, 0.77 to 2.33; adjusted OR, 2.25; 95% CI, 1.19 to 4.26). DISCUSSION: The odds of achieving good pain control was significantly better in the corounding model. However, the mechanism behind this is unexplored. This study can serve as precedence for future studies evaluating the corounding model of care.

Enhancing health benefits of bakery products using phytochemicals.

There has been a growing interest in functional bakery products with enhanced health benefits, especially the prevention of some chronic diseases such as type 2 diabetes, cardiovascular diseases and neurodegenerative disorders. Fortification of wheat flour with phytochemicals, plant components with various bio-activities, is one of the promising approaches to improving public health with the ubiquitous consumption of baked goods. This chapter reviews the current knowledge of several representative phytochemicals, mainly plant polyphenols, including catechins, anthocyanins, fucoidan and quercetin extracted from various plant resources, and their application in bakery products, regarding their stability, impact on product quality and potential health benefits.

Helicopter parenting, emotional avoidant coping, mental health, and homophobic stigmatization among emerging adult offspring of lesbian parents.

Helicopter parents are highly involved parents who hover over and around their child, applying developmentally inappropriate levels of control and tangible assistance. Previous research with different-sex parent families indicates that helicopter parenting is particularly problematic in emerging adulthood as it may indirectly affect the offspring's mental health through their use of emotional avoidant coping. Knowledge is lacking, however, on the antecedents and consequences of helicopter parenting in lesbian-parent families. The present longitudinal, questionnaire-based study investigated the effect of homophobic stigmatization in adolescence on mental health via helicopter parenting and emotional avoidant coping among 76 (37 females and 39 males) National Longitudinal Lesbian Family Study 25-year-old offspring of lesbian parents. All participants were cisgender, born in the USA, and conceived through donor sperm, with the majority being White, heterosexual, highly educated, and no longer living with their parents. Parents who reported that their offspring experienced homophobic stigmatization in adolescence were likely to enact higher helicopter parenting in emerging adulthood. Then, higher scores on helicopter parenting were associated with offspring's greater use of emotional avoidant coping, which in turn negatively affected the mental health of emerging adult offspring. Discussed in light of Bowen's family differentiation theory, the results suggest that clinicians should examine helicopter parenting in the context of lesbian parents' developmental history and potential tendency to project their own concerns about safety onto their child in order to reduce the distress of experienced homophobic stigmatization. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

The stability of psychological adjustment among donor-conceived offspring in the U.S. National Longitudinal Lesbian Family Study from childhood to adulthood: differences by donor type.

OBJECTIVE: To study differences by sperm donor type in the psychological adjustment of the U.S. National Longitudinal Lesbian Family Study (NLLFS) offspring across three time periods from childhood to adulthood. DESIGN: U.S.-based prospective cohort study. SETTING: Paper-and-pencil questionnaires and protected online surveys. PATIENT(S): A cohort of 74 offspring conceived by lesbian parents using an anonymous (n = 26), a known (n = 26), or an open-identity (n = 22) sperm donor. Data were reported when offspring were ages 10 (wave 4), 17 (wave 5), and 25 (wave 6). INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Achenbach Child Behavior Checklist administered to lesbian parents when offspring were ages 10 and 17 and the Achenbach Adult Self-Report administered to offspring at age 25. RESULT(S): In both relative and absolute stability, no differences were found in internalizing, externalizing, and total problem behaviors by donor type over 15 years. However, both externalizing and total problem behaviors significantly declined from age 10 to 17 and then increased from age 17 to 25. Irrespective of donor type, among the 74 offspring, the large majority scored continuously within the normal range on internalizing (n = 62, 83.8%), externalizing (n = 62, 83.8%), and total problem behaviors (n = 60, 81.1%). CONCLUSION(S): The results reassure prospective lesbian parents and provide policy makers and reproductive medicine practitioners with empirical evidence that psychological adjustment in offspring raised by lesbian parents is unrelated to donor type in the long term.

Adult offspring of lesbian parents: How do they relate to their sperm donors?

OBJECTIVE: To study how adult offspring in planned lesbian-parent families relate to their unknown or known donors. DESIGN: Qualitative analyses of the sixth wave of online surveys from a longitudinal study of adult offspring in planned lesbian families, enrolled at conception. SETTING: Community-based United States national study. PATIENT(S): The 76 participants were 25-year-old donor insemination (DI) offspring whose lesbian parent(s) enrolled in a prospective longitudinal study when these offspring were conceived. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Offspring were asked about donor type, feelings about permanently unknown donor, satisfaction with and role of known donor, whether relationship with known donor was ongoing, and age of meeting open-identity donor. RESULT(S): This cohort (n = 76) of DI offspring with lesbian parents was among the first generation to reach adulthood. Thirty participants had permanently unknown donors and most participants felt comfortable about not knowing them. Sixteen participants had open-identity donors they had not met. Thirty had currently known donors-met in childhood (n = 22) or after open-identity donor disclosure (n = 8)-of whom two thirds had ongoing relationships with donors, half considered their donors as acquaintances, and nearly half had good feelings about their relationship, although a minority expressed conflicted feelings. CONCLUSION(S): This study of adult DI offspring from planned lesbian families shows that those who knew their donors mainly felt positively about these relationships. Qualitative analyses offered insight into offspring-donor relationships, whose numbers are increasing due to historical and demographic trends.

Two valid and reliable short forms of the Singapore caregiver quality of life scale were developed: SCQOLS-10 and SCQOLS-15.

OBJECTIVES: The Singapore Caregiver Quality of Life Scale (SCQOLS) comprises five domains and 51 items in total. This study aimed to develop and evaluate short forms of SCQOLS. STUDY DESIGN AND SETTING: Data were collected from 612 family caregivers of patients with advanced cancers in Singapore. Exploratory factor analysis and best subset regression were used to identify candidate items for each domain. The short forms were evaluated for measurement properties. RESULTS: Inclusion of at least two items per domain in the short form gave correlation coefficients of at least 0.8 with the corresponding domain scores in the full-length version. The short forms and full-length version had similar correlation coefficients with Negative Personal Impact and Positive Personal Impact measures. Two of the five domains of the 10-item version had Cronbach's alpha ≤0.50 and test-retest reliability ≤0.65. A 15-item version of the scale with two to four items per domain performed satisfactorily in all aspects evaluated. CONCLUSION: A 15-item short form of the SCQOLS (SCQOLS-15) is valid and reliable for the assessment of the overall and domain-specific quality of life of family caregivers. A 10-item short form (SCQOLS-10) may serve as a quick, valid and reliable assessment of the overall level of quality of life.

Reference values for and interpretation of the Singapore Caregiver Quality of Life Scale: a quantile regression approach.

PURPOSE: The Singapore Caregiver Quality of Life Scale (SCQOLS) was recently developed and validated in two languages - English and Chinese. The total and domain scores are scaled to range from 0 to 100. However, the scale is not at the interval-ratio level of measurement. To facilitate interpretation, we established the percentiles of the scale's total and domain scores among family caregivers of patients with advanced cancers and demonstrate the effect size in terms of differences in relation to caregiver and patient characteristics. METHODS: Data were drawn from a cross-sectional survey of family caregivers of patients with stage III or IV solid cancers in Singapore. Quantile regression was used to estimate the percentiles in relation to caregiver and patient characteristics. RESULTS: Participants in adjacent categories of patient's performance status and caregiver's having other family members to share caregiving duties differed by 3 to 5 points in median quality of life total score and most domain scores (each Bonferroni-adjusted P, P[B], < 0.05). Ethnicity was associated with the Physical Well-being and Experience & Meaning domain scores (each P[B] < 0.05), with variable direction and magnitude. Education was associated with Mental Well-being and Financial Well-being (each P[B] < 0.05). Equations and examples for calculation of the percentiles are provided. CONCLUSION: Percentiles and effect size estimates are provided to facilitate interpretation of the SCQOLS.

Exploring the Score Equivalence of the English and Chinese Versions of the Brief Assessment Scale for Caregivers.

BACKGROUND: Multilingual outcome measures are used so that research studies are more generalizable across language contexts. OBJECTIVE: To determine the score equivalence of the English and Chinese versions of Brief Assessment Scale for Caregivers (BASC) in Singapore. METHOD: Caregivers of patients with advanced cancer completed the BASC in either English or Chinese. Multivariable linear regression analysis was used to compare the mean BASC total and factor scores between the 2 language versions, with adjustment for possible confounding variables. Equivalence was declared if the 90% confidence interval of the mean scores fell entirely within an equivalence zone of ±0.5 standard deviation. RESULTS: There were 521 ethnic Chinese participants, of whom 214 answered the English version and 307 answered the Chinese version. The BASC total and factor scores met the criteria for equivalence. Cronbach α coefficients were similar and exploratory factor analysis showed similar 2-factor structures for both language versions. CONCLUSION: The English and Chinese versions of the BASC were found to be equivalent in terms of similar adjusted mean scores, Cronbach α, and factor structures.

"We Were Among the First Non-traditional Families": Thematic Perceptions of Lesbian Parenting After 25 Years.

In the sixth wave of the U.S. National Longitudinal Lesbian Family Study (NLLFS), when their offspring were 25 years old, the parents were asked to reflect on their most challenging and best experiences raising children in non-traditional families. The responses of 131 parents were interpreted through thematic analysis. The most challenging parenting experiences fell into five major categories: (1) distress about their children's experiences of exclusion, heterosexism, or homophobic stigmatization; (2) family of origin non-acceptance of their lesbian-parent family; (3) the never-ending process of "educating the world about queer parents"; (4) homophobia or hostility toward their non-traditional family; and (5) lack of legal protections for sexual minority parent (SMP) families. Their best parenting experiences included: (1) being role models, leading to a greater acceptance of LGBTQ people; (2) treasuring the LGBTQ parent and family community; (3) teaching their children to appreciate diversity of all types; and (4) witnessing their child's pride in their non-traditional family. Some of these challenges were anticipated by the parents more than a quarter century ago at the time that they were inseminating or pregnant with the index offspring.

Mental health issues: a comparison of lesbian, bisexual and heterosexual women.

This study examines mental health issues among women of different sexual orientations. An anonymous survey was administered at 33 health care sites across the United States; the sample (N = 1304) included lesbians (n = 524), bisexual (n = 143) and heterosexual women (n = 637). Not only did sexual orientation influence the probability of experiencing emotional stress, but also whether a bisexual woman or lesbian had disclosed her sexual orientation (was "out") impacted the likelihood of having or having had mental health problems. Bisexual women and lesbians experienced more emotional stress as teenagers than did heterosexual women. Bisexual women were more than twice as likely to have had an eating disorder compared to lesbians. If a bisexual woman reported being out she was twice as likely to have had an eating disorder compared to a heterosexual woman. Lesbians who were not out and bisexual women who were out were 2-2.5 times more likely to experience suicidal ideation in the past 12 months. Lesbians and bisexual women who were not out were more likely to have had a suicide attempt compared to heterosexual women. Lesbians used psychotherapy for depression more commonly than did heterosexual or bisexual women. This is one of the few studies that compares lesbians, bisexual and heterosexual women. The implications of these findings are discussed.